Structure of the vacuum states in the presence of isovector and isoscalar pairing correlations

The long standing problem of proton-neutron pairing and, in particular, the limitations imposed on the solutions by the available symmetries, is revisited. We look for solutions with nonvanishing expectation values of the proton Δp, the neutron Δn, and the isoscalar Δ0 gaps. For an equal number of protons and neutrons we find two solutions with Δp = ± Δn, respectively. The behavior and structure of these solutions differ for spin saturated (single l shell) and spin unsaturared systems (single j shell). In the former case the BCS results are checked against an exact calculation.Facultad de Ciencias Exacta

Geothermal heating in the Panama Basin. Part II: abyssal water mass transformation

Diabatic upwelling of abyssal waters is investigated in the Panama Basin employing the water mass transformation framework of Walin [1982]. We find that, in large areas of the basin, the bottom boundary layer is very weakly stratified and extends hundreds of meters above the sea floor. Within the weakly stratified bottom boundary layer (wsBBL) neutral density layers intercept the bottom of the basin. The area of these density layer incrops increases gradually as the abyssal waters become lighter. Large incrop areas are associated with strong diabatic upwelling of abyssal water, geothermal heating being the largest buoyancy source. While a significant amount of water mass transformation is due to extreme turbulence downstream of the Ecuador Trench, the only abyssal water inflow passage, water mass transformation across the upper boundary of abyssal water layer is accomplished almost entirely by geothermal heating

Geothermal heating in the Panama Basin. Part I: hydrography of the basin

The Panama Basin serves as a laboratory to investigate abyssal water upwelling. The basin has only a single abyssal water inflow pathway through the narrow Ecuador Trench. The estimated critical inflow through the Trench reaches 0.34 ± 0.07 m s−1, resulting in an abyssal water volume inflow of 0.29 ± 0.07 Sv. The same trench carries the return flow of basin waters that starts just 200 m above the bottom and is approximately 400 m deeper than the depth of the next possible deep water exchange pathway at the Carnegie Ridge Saddle. The curvature of temperature‐salinity diagrams is used to differentiate the effect of geothermal heating on the deep Panama Basin waters that was found to reach as high as 2200 m depth, which is about 500 m above the upper boundary of the abyssal water layer

Structure of the vacuum states in the presence of isovector and isoscalar pairing correlations

The long standing problem of proton-neutron pairing and, in particular, the limitations imposed on the solutions by the available symmetries, is revisited. We look for solutions with non-vanishing expectation values of the proton, the neutron and the isoscalar gaps. For an equal number of protons and neutrons we find two solutions where the absolute values of proton and neutrons gaps are equal but have the same or opposite sign. The behavior and structure of these solutions differ for spin saturated (single l-shell) and spin unsaturared systems (single j-shell). In the former case the BCS results are checked against an exact calculation.Comment: 19 pages, 5 postscript figure

Electrical properties of stoichiometric BiFeO3 prepared by mechanosynthesis with either conventional or spark plasma sintering

Phase-pure powders of stoichiometric BiFeO3 have been prepared by mechanosynthesis. Ceramics sintered by either conventional heating in air or spark plasma sintering (SPS) followed by oxidative anneal in air are highly insulating with conductivity e.g. ~10–6 Scm–1 at 300 °C and activation energy 1.15(2) eV, which are comparable to those of a good-quality BiFeO3 single crystal. By contrast, the as-prepared SPS sample without the post-sinter anneal shows higher conductivity e.g. ~10–6 Scm–1 at 225 °C and lower activation energy 0.67(3) eV, indicating some reduction of the sample by the SPS process. The reason for the high conductivity observed in some ceramic samples reported in the literature appears to be unclear at presentGobierno de España CTQ 2011-27626 MAT 2008-06619Junta de Andalucia TEP-0300

The probiotic strain Shewanella putrefaciens Pdp11 strongly modulates gene expression of the fish pathogen Vibrio harveyi

In this work, the interaction between the fish probiotic Shewanella putrefaciens Pdp11 and the fish pathogen V. harveyi was studied by RNA-seq to understand how SpPdp11 interferes with the pathogen through bioinformatics analysis. Three types of cultures were performed: SpPdp11 alone, V. harveyi alone and SpPdp11 and V. harveyi together. RNA was extracted and sequenced (paired end, 2x75 bp) at the Ultrasequencing Service of the University of Málaga using the Illumina NextSeqTM 550 platform. Raw reads were processed using a bioinformatic pipeline and a network analysis was performed for the most relevant functional enrichment results. The results suggest that the presence of SpPdp11 affects V. harveyi to a greater extent than V. harveyi affects SpPdp11. Considering that V. harveyi is a pathogenic strain and SpPdp11 is a probiotic strain, this may be positive for its probiotic capacity, as it not only maintains its functionality almost intact, but also produces a huge imbalance in that of V. harveyiThis work was funded by project AG-2017-509 83370-C3-3-R (MINECO, Spain)

Structure of the vacuum states in the presence of isovector and isoscalar pairing correlations

The long standing problem of proton-neutron pairing and, in particular, the limitations imposed on the solutions by the available symmetries, is revisited. We look for solutions with nonvanishing expectation values of the proton Δp, the neutron Δn, and the isoscalar Δ0 gaps. For an equal number of protons and neutrons we find two solutions with Δp = ± Δn, respectively. The behavior and structure of these solutions differ for spin saturated (single l shell) and spin unsaturared systems (single j shell). In the former case the BCS results are checked against an exact calculation.Facultad de Ciencias Exacta