Dynamics of quantum entanglement in the reservoir with memory effects

The non-Markovian dynamics of quantum entanglement is studied by the Shabani-Lidar master equation when one of entangled quantum systems is coupled to a local reservoir with memory effects. The completely positive reduced dynamical map can be constructed in the Kraus representation. Quantum entanglement decays more slowly in the non-Markovian environment. The decoherence time for quantum entanglement can be markedly increased by the change of the memory kernel. It is found out that the entanglement sudden death between quantum systems and entanglement sudden birth between the system and reservoir occur at different instants.Comment: 14 pages, 3 figure

Permittivity of (40 nm and 80 nm) alumina nanofluids in ethylene glycol at different temperatures

This article studies the effective permittivity of alumina nanofluids (aluminium oxide) in ethylene glycol. Two nanoparticle sizes (40 nm and 80 nm) were considered and the measurements were carried out at various concentrations (up to 2% in volume) and at six different temperatures (from 298.15 K to 348.15 K). An empirical equation is proposed that allows to obtain the permittivity value at any concentration or temperature in the studied ranges. The influence of the volume fraction, nanoparticle size and the temperature on relative permittivity is shown. When compared to the previous published values for alumina (40 nm) in water, current results show the influence of the base fluid. The enhancement of permittivity was calculated, and its behaviour was analysed. Smaller sized particles have the highest values of permittivity and enhancement. Theoretical models in the study of permittivity are applied. The poor predictions of classical models are attributed to the positive behaviour of the permittivity change on mixing for these nanofluids. The contributions to permittivity from ethylene glycol and nanoparticles are separated in two distinct terms in the variable index equation. The permittivity change on mixing calculated from this equation points out that the nanoparticles are the main responsible for the unusual permittivity increment in these colloids.We appreciate the financial support ED431C 2020-06 provided by the Xunta de Galicia (Spain). M.F.C. thanks Instituto Superior de Engenharia do Porto for granting leave of absence to carry out experimental work at University of Vigo.info:eu-repo/semantics/publishedVersio

Regional metacommunities in two coastal systems: spatial structure and drivers of plant assemblages

Aim Biogeographical patterns in metacommunities are still poorly understood, and different processes are expected to occur in different habitats. We analysed the regional plant metacommunities of coastal habitats to test whether (1) the influence of space and climate differs between two habitats differentiated along the seashore–inland gradient, and (2) regional variation in species composition of these habitats can be ascribed to different metacommunity paradigms. Location The entire coast of the Iberian Peninsula, south-western Europe. Methods We collected data on the plant species composition of coastal sites on sand dunes across 3000 km of coastline. The sites were classified into two habitats corresponding to shifting and stable sand dunes, and divided into three distinct geographical regions: Cantabrian, Atlantic and Mediterranean. We assessed the geographical structure of the species composition using ordination, estimates of species turnover and spatial autocorrelation. We then used multivariate models and variation partitioning to test the influence of climatic and spatial effects. Analyses were conducted for the whole data set and the geographical subsets. Results Metacommunities from shifting and stable dunes showed similar spa- tial patterns, with the highest species turnover occurring in the Mediterranean region. Similarities between communities that were nearer each other (typically < 100 km) were weaker in shifting than in stable dunes, although the distance decay for sites that were further apart was similar in both habitats. Variation in species composition in shifting dunes was mainly explained by distance and climate, while in stable dunes the effect of climate was clearly dominant. The observed differences were relatively consistent across geographical regions. Main conclusions Distinct processes structure the metacommunities in two dune habitats differentiated along the seashore–inland gradient. Communities of shifting dunes seem to be structured by an interplay of neutral or patch-dynamic processes and to a lesser degree by species sorting. In contrast, communities of stable dunes are mainly governed by species sorting in response to climatic gradi- ents. These results highlight the importance of differentiating habitats according to local ecological factors when analysing regional patterns in metacommunities

Columnas líquidas en condiciones de ingravidez : informe final 1981

Columnas líquidas en condiciones de ingravidez : informe final 198

Plasmonic LED device

Plasmonic nanostructures are known to influence the emission of near-by emitters. They can enhance the absorption and modify the external quantum efficiency of the coupled system. To evaluate the possibility of using plasmonics to enhance the light emission of a phosphor-converted LED device and create an efficient directional light source, regular arrays of aluminium nanoparticles covered with a red dye layer are investigated. In arrays of aluminum nanocylinders with a diameter of ca 140 nm combined with a thin (650 nm) layer of luminescent material, very narrow resonances have been observed, which lead to large enhancement factors of up to 70 and 20 for excitation with a directional blue laser source and a lambertian LED respectively, in a small spectral range for particular angles. The measured resonances agree very well with finite-difference time-domain numerical simulations. These changes in the angular emission profile of the red dye as well as the spectral shape of its emission can help to optimize the efficacy of phosphor-converted LED modules and increase the amount of useable light in a certain angular cone. Using Fourier microscopy, large modifications of the angular emission profile as well as spectral shaping are observed for these plasmonic LED devices if compared to reference samples without plasmonic nanostructures

Desarrollo de un dispositivo intravaginal para la recogida de semen en ganado ovino

Publishe

Valores antropométricos en niños con celiaquía diagnosticados precozmente

Peer Reviewe

Inclusion of fat in the diet of primiparous sows: effect on the reproduction and litter performance

La incorporación de grasa en la dieta podría mejorar la performance reproductiva de cerdos en producción, principalmente durante las épocas más calurosas. Para comprobar esta hipótesis se evaluó el efecto de la inclusión de grasa a diferentes niveles sobre variables reproductivas de cerdas primíparas en condiciones de subtrópico. Se utilizaron 3 grupos de 6 animales (n=18) a los cuales se les suministraron 3 dietas con diferentes niveles de inclusión de grasa (0%, 3,5% y 7%) desde el día 90 de gestación y durante la lactación (21 días). Las variables medidas fueron el número de lechones nacidos totales, nacidos vivos, muertos y peso de la camada al nacimiento y al destete, mientras que sobre las hembras se registró el intervalo de retorno al celo. Se empleó un diseño completamente aleatorizado y los datos fueron analizados mediante ANOVA con el software estadístico Infostat®. No se encontraron diferencias al incorporar grasa, en relación al número de lechones nacidos vivos, muertos, totales, peso al nacimiento e intervalo-destete celo (p>0,05) mientras que el número y peso de lechones al destete se vio influenciado de manera significativa (p<0,05). En conclusión, la adición de grasa en dietas de cerdas primíparas no afecta variables al nacimiento ni el intervalo detete-celo, pero mejora el número y peso de los lechones al destete.Adding fat to sow diets may improve reproductive performance during the warm season. Therefore, the objective of this study was to evaluate the effect of fat addition at different levels on reproductive variables of primiparous sows in subtropical conditions. Three groups of six animals (n=18) were fed with three diets with different fat levels (0%, 3.5% and 7%) from day 90 of gestation until the end of lactation (21 days). Litter size, weight and number of piglets born alive and stillborn were recorded, as well as weight and number of pigs at weaning, along with weaning-to-estrus interval. Completely random design was used, and collected data were analyzed using Infostat® statistical software. ANOVA was used for means comparison. No differences between treatments were observed among number and weight of pig born alive, stillborn, litter size and weaning-to-estrus interval (p&gt;0.05), whereas number and weight of pigs at weaning were increased by the addition of fat (p&lt;0.05). In conclusion, fat inclusion resulted in an improved number and weight of piglets at weaning; however, weaning-to-estrus and variables at birth, were not affected.Facultad de Ciencias Veterinaria