1,545 research outputs found
Designing oxynitride nanostructured thin films to enhance europium white light emission for efficient solid state emitters
CLEO®/Europe-EQEC 2015, Munich (ICM), Germany, June 21st, - 25th, 2015; http://2015.cleoeurope.org/In the present work we study the visible light emission of europium (Eu) ions embedded in two different matrices (amorphous aluminum oxide (a-Al2O3) and ceramic SiAlON) as a function of the Eu distribution and concentration. Eu-doped thin films were produced using the pulsed laser deposition technique by the alternating ablation of the matrix target and the Eu target; as a result nanostructured Eu-doped
multilayers were formed. The Eu in-depth distribution was modified by varying the host inter-layer thickness, which ranged from 1 to 15 nm, and the Eu content per layer was modified by varying the number of pulses on the Eu target.
Under UV excitation (355 nm), the as-deposited films of both matrices showed a broadband emission (FWHM ¿200 nm), that has been related to the superposition of the 5d levels to the 4f levels of the Eu2+, which is rarely found in pure oxides. This broad emission was further enhanced keeping the same spectral distribution upon annealing treatments up to 500 oC for the a-Al2O3 (Fig. 1a) and 700 oC for the SiAlON (Fig. 1c). However for samples with higher Eu content and at the higher annealing temperatures the spectral shape emission changed and the emission spectra showed narrow and well-defined emission peaks. These have been identified as resulting from the 4f ¿ 4f transitions of Eu3+ (Fig.
1b). Therefore, it has been found that two distinct and efficient Eu-related emissions can be obtained by a suitable design of the Eu distribution and concentration. This is due to a change of oxidation state of Eu in the films, which will be discussed. These Eu-doped films have a high potential for the development of either solid state lighting LEDs with broadband emission, or integrated lasers with narrow emission lines.
Acknowledgements. This work has been financially supported by the Spanish Ministry of Economy and Competitiveness through the project TEC2012_38901-C02-01. I.C. acknowledges the financial support through JAE-Pre-2011_00578. A.M. acknowledges the financial support through BES-2013-062593.This work has been financially supported by the Spanish Ministry of Economy and Competitiveness through the
project TEC2012_38901-C02-01. I.C. acknowledges the financial support through JAE-Pre-2011_00578. A.M. acknowledges the
financial support through BES-2013-062593.Peer Reviewe
The rocaille victory: the chapel altarpiece of the Sagrada Familia school in Seville, Francisco de Acosta el Mayor’s work
Vinculamos el retablo de la capilla del colegio Sagrada Familia de Sevilla a Francisco de Acosta “el Mayor”, el cual procede del conjunto que hizo para el Carmen Calzado de Carmona entre 1770 y 1772 y que actualmente se encuentra disperso.We link the altarpiece at Sagrada Familia School’s chapel in Seville to Francisco de Acosta “el Mayor”, which proceeds from the set that he built for the Carmen Calzado Convent in Carmona between 1770 and 1772 and that is dispersed nowadays
Cloning and expression of a Saccharomyces cerevisiae RNA-dependent RNA polymerase
RNA-dependent RNA polymerases (RdRp) are ubiquous enzimes first described in RNA viruses and virus-like elements. In Saccharomyces cerevisiae this enzyme can be found, fused with capsid proteins, encoded by the L-A helper virus-like particle. Replication cycle of L-A is coupled to that of M satellite particle, which confers a killer phenotype to the yeast (Schmitt & Breinig, 2002). RdRp recognizes and replicates ssRNA from both L-A and M virus. RdRp recognizes a 3'-Terminal Recognition Element (3'TRE), a small stem-loop 5 bases from the 3' end (Ribas, Fujimuras, & Wickner, 1994), which can be used as an effective tool for primerless replication of RNA molecules. To gain further insight on the virus-like particle replication mechanism and to evaluate its possible biotechnological application, the present project is focused on cloning the RdRp coding sequence in several different expression vectors and expressing the protein using different Escherichia coli strains as hosts. Once RdRp is efficiently expressed, we will proceed to purify it by affinity chromatography and test the protein activity by replicating full length viral RNA´s and other RNA sequences with or without the 3'TRE sequence. In our communication we will present our advances in cloning, expression, purification and activity of the yeast polymeras
Development of a prototype for submarine communications in shallow waters
The Telecommunications Marine Laboratory (TML) of the University of
Cádiz takes part in a research project to study the intertidal sediments of the Bay
of Cádiz. The collection of samples from the seabed and the transmission of data
to the surface are performed by a Mini Profiler with four channels (MP4), which is
supplied by UNISENSE. Each channel processes the samples collected by a single
sensor. For power, control, and data transmission, a special wiring that connects the
submerged subsystem with the surface subsystem is used. The tension transmitted
by the cable to the MP4 structure makes its handling and positioning under water
more difficult. This article explains the technological solution developed by the TML
to replace some wiring from the MP4. For the prototype, two underwater acoustic
modems have been used and an electronic system has been developed based on the
Arduino platform, in order to multiplex, digitize, and transmit the data collected by
the MP4 sensors, eliminating the need to use wiring. The submerged subsystem has
an autonomous power supply by a battery.Peer Reviewe
Improved wear performance of ultra high molecular weight polyethylene coated with hydrogenated diamond like carbon
Hydrogenated diamond like carbon (DLCH) thin films were deposited on medical grade ultra high molecular weight polyethylene (UHMWPE) by radio frequency plasma enhanced chemical vapor deposition. The DLCH coating thicknesses ranged from 250 to 700. nm. The substrates were disks made of UHMWPEs typically used for soft components in artificial joints, namely virgin GUR 1050 and highly crosslinked (gamma irradiated in air to 100. kGy) UHMWPEs. Mechanical and tribological properties under bovine serum lubrication at body temperature were assessed on coated and uncoated polyethylenes by means of nano-hardness and ball-on-disk tests, respectively. Morphological features of the worn surfaces were obtained by confocal microscopy and scanning electron microscopy. This study confirms an increase in surface hardness and good wear resistance for coated materials after 24. h of sliding test compared to uncoated polyethylene. These results point out that to coat UHMWPE with DLCH films could be a potential method to reduce backside wear in total hip and knee arthroplasties.Ministerio de Ciencia y Educación MAT2006-12603- C02-01, CSD2008-0002
Gobierno y eficiencia de las cajas de ahorro espa¤olas
El presente trabajo analiza la relaci¢n existente entre la composici¢n y estructura de los ¢rganos de gobierno de las cajas de ahorros espa¤olas y su eficiencia en el a¤o 1999. Utilizando ecuaciones tobit los resultados del estudio constatan la existencia de una relaci¢n negativa entre la participaci¢n de las administraciones p£blicas en el consejo de administraci¢n de las cajas y su eficiencia en costes calculada, alternativamente, a trav‚s de un modelo de frontera eficiente y de la ratio gastos de explotaci¢n entre margen ordinario. Asimismo se evidencia una relaci¢n positiva entre la participaci¢n de pol¡ticos en el consejo y la canalizaci¢n de mayores recursos financieros hacia obras sociales.Teor¡a de la agencia; gobierno corporativo; consejo de administraci¢n; cajas de ahorros; eficiencia
Overexpression of SepJ alters septal morphology and heterocyst pattern regulated by diffusible signals in Anabaena.
Filamentous, N2 -fixing, heterocyst-forming cyanobacteria grow as chains of cells that are connected by septal junctions. In the model organism Anabaena sp. strain PCC 7120, the septal protein SepJ is required for filament integrity, normal intercellular molecular exchange, heterocyst differentiation, and diazotrophic growth. An Anabaena strain overexpressing SepJ made wider septa between vegetative cells than the wild type, which correlated with a more spread location of SepJ in the septa as observed with a SepJ-GFP fusion, and contained an increased number of nanopores, the septal peptidoglycan perforations that likely accommodate septal junctions. The septa between heterocysts and vegetative cells, which are narrow in wild-type Anabaena, were notably enlarged in the SepJ-overexpressing mutant. Intercellular molecular exchange tested with fluorescent tracers was increased for the SepJ-overexpressing strain specifically in the case of calcein transfer between vegetative cells and heterocysts. These results support an association between calcein transfer, SepJ-related septal junctions, and septal peptidoglycan nanopores. Under nitrogen deprivation, the SepJ-overexpressing strain produced an increased number of contiguous heterocysts but a decreased percentage of total heterocysts. These effects were lost or altered in patS and hetN mutant backgrounds, supporting a role of SepJ in the intercellular transfer of regulatory signals for heterocyst differentiation
Impact of concurrent pregnancy and lactation on maternal nestbuilding, estradiol and progesterone concentrations in rabbits
[EN] We evaluated the impact of concurrent pregnancy and lactation on: nest-building (i.e., digging, straw-carrying, hair-pulling), food intake, milk output, body weight, and the concentration of estradiol and progesterone in blood. Digging was lower in pregnant-lactating (PL) rabbits, compared with pregnant-only (PO) does, on 21-23 d (52±64 vs. 104±86 g, respectively; mean±SD; P<0.05). Straw-carrying was also reduced in PL does on 24-26 d (9±27 vs. 79±94 g; P<0.005), 27-29 (27±56 vs. 99±77 g; P<0.005), and in the total amount of material introduced into the nest box (132±167 vs. 286±217 g; P<0.02). Hair-pulling was expressed by practically all animals. Food intake declined in PO does on the three days preceding parturition (P<0.01) and increased markedly during lactation; this increase was much larger in PL than in lactating-only (LO) rabbits (P<0.01). Milk output was similar between PL and LO does during the first 21 d of lactation but a marked decline in this parameter occurred in PL does from then until 30 d. The differences in nest-building between PL and PO rabbits may be related to the concentrations of estradiol and progesterone on specific days of pregnancy. PL does showed significantly higher estradiol levels than PO animals on pregnancy 1 d (33±13 vs. 23±4 pg/mL; P<0.02) and 21 (34±19 vs. 24±6 pg/mL; P<0.05) and also higher levels of progesterone on pregnancy 1 d (4±5 vs. 1±2 ng/mL; P<0.05). However, PL rabbits had lower levels of progesterone on 7 d (6±3 vs. 9±2 ng/mL; P<0.02) and 14 d (8±3 vs. 11±3 ng/mL; P<0.005) than PO does. Our results indicate that the unique endocrine milieu of PL rabbits has a direct bearing on specific behavioral and physiological phenomena that impact productivity on the farm.González-Mariscal, G.; Gallegos, J.; Sierra-Ramírez, A.; Garza Flores, J. (2009). Impact of concurrent pregnancy and lactation on maternal nestbuilding, estradiol and progesterone concentrations in rabbits. World Rabbit Science. 17(3):145-152. doi:10.4995/wrs.2009.65414515217
El control de los criterios de higiene de los procesos en mataderos de cerdo ibérico como medio para evaluar el funcionamiento aceptable de la producción
La normativa vigente obliga a los mataderos de cerdo ibérico a desarrollar e implantar un plan APPCC (Análisis de Peligros y Puntos de Control Crítico). De igual modo deben comprobar el correcto funcionamiento de su proceso de producción realizando controles microbiologícos de la superficie de las canales, siguiendo un plan de muestreo diseñado de acuerdo al Reglamento 2073/2005. En el presente trabajo se expone el diseño de un plan de muestreo de un matadero de cerdo ibérico, y se muestran los resultados obtenidos en los primeros controles realizados siguiendo dicho plan
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