Mecanismos de proyecto medievales. El caso cordobés a partir de sus parroquias

Se realiza un acercamiento a la planta de algunas iglesias parroquiales de Córdoba, comenzadas a construir a finales del siglo XIII. Por sus semejanzas, es posible suponer criterios de diseño comunes para la generación de su traza. Los planteamientos tienen en cuenta el modus operandi medieval, del que es buen ejemplo el 'Álbum de Villard', prestándose especial atención a uno de sus dibujos, el croquis de una planta cisterciense. Los resultados apuntan el uso de un sencillo modelo que permitirá generar la planta de todo un conjunto de edificios, los cuales estructurarían el tejido urbano de la ciudad bajomedieval

Integral Field Spectroscopy based H\alpha\ sizes of local Luminous and Ultraluminous Infrared Galaxies. A Direct Comparison with high-z Massive Star Forming Galaxies

Aims. We study the analogy between local U/LIRGs and high-z massive SFGs by comparing basic H{\alpha} structural characteristics, such as size, and luminosity (and SFR) surface density, in an homogeneous way (i.e. same tracer and size definition, similar physical scales). Methods. We use Integral Field Spectroscopy based H{\alpha} emission maps for a representative sample of 54 local U/LIRGs (66 galaxies). From this initial sample we select 26 objects with H{\alpha} luminosities (L(H{\alpha})) similar to those of massive (i.e. M\ast \sim 10^10 M\odot or larger) SFGs at z \sim 2, and observed on similar physical scales. Results. The sizes of the H{\alpha} emitting region in the sample of local U/LIRGs span a large range, with r1/2(H{\alpha}) from 0.2 to 7 kpc. However, about 2/3 of local U/LIRGs with Lir > 10^11.4 L\odot have compact H{\alpha} emission (i.e. r1/2 < 2 kpc). The comparison sample of local U/LIRGs also shows a higher fraction (59%) of objects with compact H{\alpha} emission than the high-z sample (25%). This gives further support to the idea that for this luminosity range the size of the star forming region is a distinctive factor between local and distant galaxies of similar SF rates. However, when using H{\alpha} as a tracer for both local and high-z samples, the differences are smaller than the ones recently reported using a variety of other tracers. Despite of the higher fraction of galaxies with compact H{\alpha} emission, a sizable group (\sim 1/3) of local U/LIRGs are large (i.e. r1/2 > 2 kpc). These are systems showing pre-coalescence merger activity and they are indistinguishable from the massive high-z SFGs galaxies in terms of their H{\alpha} sizes, and luminosity and SFR surface densities.Comment: Accepted for publication in A&A. (!5 pages, 7 figures, 2 tables

El plancton de las lagunas de gravera y el fósforo : el enriquecimiento de las paradojas

Durante las últimas décadas se han formulado explícitamente varias hipótesis sobre el funcionamiento de las comunidades pelágicas lacustres en relación con el enriquecimiento en fósforo. Entre ellas, se cuentan: 1ª) la relación directa entre fósforo y biomasa planctónica, 2ª) los máximos de la riqueza específica planctónica a niveles intermedios de fósforo, 3ª) la desestabilización de los grupos funcionales de la red trófica debida al enriquecimiento en fósforo (ó "paradoja del enriquecimiento"), 4ª) el hecho de que la biomasa planctónica en todos los niveles sea el resultado de la interacción entre el recurso limitante (el fósforo, en este caso) y la red trófica encabezada por los peces ictiófagos, y 5ª) la marcada influencia del enriquecimiento y de los peces ictiófagos sobre el espectro de tamaños planctónicos. Con objeto de comprobar estas hipótesis, realizamos un estudio estacional durante año y medio sobre el plancton de 16 lagunas de gravera situadas en el valle del río Jarama (Madrid), las cuales presentan un gradiente claro de fósforo total promedio (36-2500 μg P/L) y pueden o no albergar peces ictiófagos, aunque casi todas tengan ciprínidos. La 1ª hipótesis sólo se cumplió para bacterias, fitoplancton y rotíferos, pero no para las restantes comunidades planctónicas. La 2ª hipótesis se refutó, pues los máximos de riqueza específica se presentaron en las lagunas hipertróficas. La 3ª hipótesis no se comprobó y, en el caso de bacterias y fitoplancton consumible por herbívoros, tuvo lugar una estabilización de los mismos con el aumento de fósforo; probablemente, el efecto estabilizador de la omnivoría debida a copépodos y a ciprínidos fuera el responsable de este resultado. Los peces ictiófagos afectaron favorablemente a la biomasa de cladóceros, no alcanzando su efecto a los niveles inferiores de la red, controlados claramente por el fósforo, lo cual prestó apoyo a la idea de la interacción entre fuerzas ascendentes y descendentes de la red trófica, pero refutó la idea de la cascada trófica. Tanto el fósforo como los peces ictiófagos influyeron sobre el espectro de tamaños de modo antagónico, lo cual complicó la 5ª hipótesis. La conclusión general de este ejercicio de contraste de hipótesis es -además de la obvia de continuar investigando las redes tróficas planctónicas- que necesitamos hipótesis más globales en apoyo epistemológico de este enriquecimiento de las paradojas que hemos observado.Several hypotheses have been outlined on the relationship of lake communities and phosphorus enrichment in recent years. Some of them are the following: i) a positive relationship between phosphorus and planktonic biomass, ii) species richness peaks at intermediate phosphorus concentrations, iii) the destabilisation of food web functional groups arising from phosphorus enrichment (called the paradox of enrichment), iv) the plankton biomass as the outcome of interactions between the limiting resource (phosphorus in most lakes) and the food web, and v) the remarkable influence of phosphorus enrichment and piscivorous fish on planktonic size spectra. To test these hypotheses, we carried out a seasonal study on plankton communities of sixteen gravel-pit lakes for fifteen months in the river Jarama plain (Madrid, Central Spain). These lakes showed a wide range of average phosphorus contents (36-2500 μg P/L), piscivorous fish lived in some of them and most harbour benthic, omnivorous ciprinids. Hypothesis i was only demonstrated for bacteria, phytoplankton and rotifers. Hypothesis ii was refuted since species richness peaks occurred in hypertrophic lakes. Hypothesis iii was not supported by our data, and we even found a stabilisation of bacterial and edible phytoplankton populations along with phosphorus enrichment, such a stabilisation being a likely result of omnivory by copepods and ciprinids. As expected, piscivorous fish influenced cladoceran and bacterial density whereas phosphorus enrichment increased phytoplankton biomass, but the top-down effect did not affect phytoplankton, rotifers and copepods, thus supporting the bottom-up:top-down model against the trophic cascade model. Both phosphorus and piscivorous fish impinged on planktonic size spectra, albeit in an antagonistic way, and hence hypothesis v must be made more comprehensive. In addition to the obvious necessity of further studies on planktonic food webs, this exercise of hypothesis testing suggests that more comprehensive hypotheses should be built to support epistemologically the enrichment of paradox observed

Effect of shear processing on the linear viscoelastic behaviour and microstructure of bitumen/montmorillonite/MDI ternary composites

Polymer modified bitumens (PMBs) have largely been utilized as a construction material. However, lack of affinity between bitumen and polymer leads to phase separation, and eventually, performance depletion. In this paper, alternative formulations of bitumen with an organically-modified montmorillonite (OMMT) Cloisite 20A® and polymeric methylene diphenyl diisocyanate (MDI) were prepared by melt blending. Their comprehensive rheological characterization evidenced improved linear viscoelastic properties when OMMT is added, revealing a noticeable structural reinforcement and thermal stability. Rheological data also showed that MDI-involved reactions control the composite end properties, being greatly influenced by the shear conditions applied

GROWTH AND SURVIVAL OF 0 + ABFT Thunnus thynnus FINGERLINGS KEPT IN TANKS

This article shows the most relevant results obtained between August 2017 and October 2018 with two batches of 0+ tunas: cultured tunas (CT) born in the IEO facilities in June 2017 and wild tunas (WT) captured in Mazarron Bay in September 2017. Fertilized ABFT eggs were collected from cages owned by PisciAlba and obtained larvae were cultured in IEO facilities. At the end of July 2017, 500 fingerlings (CT, 2 g average weight) were move to ICRA facilities on 29th July and placed in a 1000 m3 tank. At the end of September 2017 mean weight were 350 gr. In that moment, a total of 68 0+ ABFT fingerlings (WT, 414 g mean weight), were captured from the Mazarron Bay and placed in a 3500 m3 tank in ICRA. From this moment temperature ranged between 18 and 27ºC, and feeding consisted in bait, mainly Sardinella aurita and Scomber scombrus, but also Scomber japonicus, Engraulis encrasicolus and Clupea harengus. During November 2017, mortality increased in CT without any symptoms of infectious disease. 80 healthier CT were then moved to a greater tank (2500 m3 ) and in March 2018, when completely recovered, they were placed together with WT and both batches were cultured in the same tank up to now. During the 13 months period mortality observed in CT was high (close to 85%) while mortality in WT was lower than 15%. Growth was also slightly faster in WT. Feeding intake ranged during the whole period between 3 and 26%, and feeding conversion rate estimated was close to 12. At the end of October 2018 mean weight of population was 11 kg

Electron refraction at lateral atomic interfaces

We present theoretical simulations of electron refraction at the lateral atomic interface between a “homogeneous” Cu(111) surface and the “nanostructured” one-monolayer (ML) Ag/Cu(111) dislocation lattice. Calculations are performed for electron binding energies barely below the 1 ML Ag/ Cu(111) M-point gap (binding energy EB ¼53 meV, below the Fermi level) and slightly above its C -point energy (EB ¼160 meV), both characterized by isotropic/circular constant energy surfaces. Using plane-wave-expansion and boundary-element methods, we show that electron refraction occurs at the interface, the Snell law is obeyed, and a total internal reflection occurs beyond the critical angle. Additionally, a weak negative refraction is observed for EB ¼53 meV electron energy at beam incidence higher than the critical angle. Such an interesting observation stems from the interface phase-matching and momentum conservation with the umklapp bands at the second Brillouin zone of the dislocation lattice. The present analysis is not restricted to our Cu-Ag/Cu model system but can be readily extended to technologically relevant interfaces with spinpolarized, highly featured, and anisotropic constant energy contours, such as those characteristic for Rashba systems and topological insulators. Published by AIP Publishing.Peer ReviewedPostprint (published version