Mechanisms for photon sorting based on slit-groove arrays

Mechanisms for one-dimensional photon sorting are theoretically studied in the framework of a couple mode method. The considered system is a nanopatterned structure composed of two different pixels drilled on the surface of a thin gold layer. Each pixel consists of a slit-groove array designed to squeeze a large fraction of the incident light into the central slit. The Double-Pixel is optimized to resolve two different frequencies in the near infrared. This system shows a high transmission efficiency and a small crosstalk. Its response is found to strongly depend on the effective area shared by overlapping pixels. Three different regimes for the process of photon sorting are identified and the main physical trends underneath in such regimes are unveiled. Optimal efficiencies for the photon sorting are obtained for a moderate number of grooves that overlap with grooves of the neighbor pixel. Results could be applied to optical and infrared detectors.Comment: 12 pages, 4 figure

Transmittance of a subwavelength aperture flanked by a finite groove array \\ placed near the focus of a conventional lens

One-dimensional light harvesting structures illuminated by a conventional lens are studied in this paper. Our theoretical study shows that high transmission efficiencies are obtained when the structure is placed near the focal plane of the lens. The considered structure is a finite slit-groove array (SGA) with a given number of grooves that are symmetrically distributed with respect to a central slit. The SGA is nano-patterned on an opaque metallic film. It is found that a total transmittance of 80% is achieved even for a single slit when (i) Fabry-Perot like modes are excited inside the slit and (ii) the effective cross section of the aperture becomes of the order of the full width at half maximum of the incident beam. A further enhancement of 8% is produced by the groove array. The optimal geometry for the groove array consists of a moderate number of grooves ($\geq 4$) at either side of the slit, separated by a distance of half the incident wavelength $\lambda$. Grooves should be deeper (with depth $\geq \lambda/4$) than those typically reported for plane wave illumination in order to increase their individual scattering cross section.Comment: 7 pages, 6 figure

Morfología macroscópica de alteración de la piedra de la Catedral de Guadix/España

Los principales factores de alteración que afectan a la catedral de Guadix son de origen natural, fundamentalmente térmico e hidráulico, por sus grandes oscilaciones de temperatura en verano y por la frecuencia de heladas en invierno, y por la lluvias. Los litotipos empleados son principalmente calcarenitas de porosidad media y calizas algo más compactas, procedentes de canteras de la zona, y mármoles. Los mecanismos de alteración correspondientes son los de dilatación térmica diferencial originados por los saltos térmicos, en especial en las piedras más compactas, los de incremento de volumen en capilares e intersticios, sobre todo por heladicidad, y los de disolución. Los indicadores de alteración más graves son las fisuras y fragmentaciones que afectan a los elementos más labrados y que han llevado al estado de ruina a la mayor parte de los elementos más aireados como los pináculos.The main factors of deterioration that affect the Cathedral of Guadix are of a natural origin, basically thermic and hidraulic, due to its great oscillations in temperature in Summer, the frecuency of frosts in Winter and the rains. The lithotypes employed are mainly calcarenite of mean porosite and slightly more compact limestones from the quarries in the área, and marbles. The corresponding deterioration mecanisms are those of diferential thermic dilatations caused by thermic jumps, especially in the more compact stones, those of increase in volume in capillaries and interstices, especially by freezing, and those of dissolution. The most serious deterioration indicators are fissures and spalling that affect the most carved elements and which have taken the greater part of the most aerated elements such as the pinnacles to a state fo ruin

Morfología macroscópica de alteración de la piedra de la Catedral de Almería/España

Los vientos reinantes en la zona, asociados a una importante humedad ascendente, son los principales factores naturales de alteración que afectan a la Catedral de Almería. Pueden señalarse como factores antropogénicos de alteración ciertas desafortunadas labores de mantenimiento llevadas a cabo, así como, aunque con carácter episódico, los bombardeos y ametrallamientos sufridos por el edificio durante la guerra civil. El único litotipo empleado en la construcción es una caliza dolomítica de elevada porosidad procedente de canteras próximas a la ciudad. Los principales mecanismos de alteración son los de incremento de volumen en capilares e intersticios, ligados a la presencia de sales, y los de disolución, dada la solubilidad de las sales de magnesio de constitución, que pueden producir la desdolomitización de la piedra. Esto conduce a unos indicadores de alteración con una morfología típica consistente en huecos en todas sus manifestaciones: picados, alveolizaciones y cavernas. La mayor degradación se da en las partes altas y bajas del edificio, allí donde los factores viento y humedad, respectivamente, son más intensos. La alteración antropogénica también toma, casi irónicamente, la forma de huecos, como los impactos de balas y obuses de la fachada Sur y las regolas practicadas para cables eléctricos en todo el edificio. Diversas restauraciones han introducido tensiones en los materiales que han conducido a decohesiones en diversos grados (desagregaciones, disgregaciones y arenizaciones) en el interior del templo y en el claustro. El edificio se encuentra en un estado de alteración de cierta significación que esencialmente afecta a la estética del mismo. La velocidad del proceso degradativo observada en ciertas áreas del mismo, en particular en las restauradas, reclama actuaciones urgentes para su mantenimiento.The prevailing winds in the área, associated with an important rising damp are the main natural factors of deterioration that affect the Cathedral of Almería. Certain unfortunate maintenance Jobs carried out as well as the bombardments and machine-gunning on the building during the Civil War can be indicated as anthropogenical factors of deterioration. The only lithotype used in the construction is a dolomitic limestone of high porosity from quarries near the city. The increase in volume in capillaries and interstices, related whith the presence of salts, and the dissolution, due to the great solubility of the natural magnesium salts which can produce dedolomitization of the stone, are the main deterioration mechanisms. This leads to indicators of deterioration with a typical morphology consisting of openings in all its manifestations (pitting, alveolar erosions and craters) especially on the high and low parts of the building where the wind and humidity, respectively, are more intense. The anthropogenical deterioration also has the shape of openings, such as the impact of bullets and obuses on the Southern fagade and the grooves made for electric cables throughout the building. Diverse restorations have introduced tensions in the materials which have led to decohesions at different degrees (disaggregations, disintegrations and grain disgregations) in the interior of the temple and cloister

Morfología macroscópica de alteración de la piedra de la Catedral de Sevilla/España

El litotipo mayoritariamente empleado en la construcción de la Catedral de Sevilla es la calcarenita del Puerto de Santa María seguida de la caliza de Espera. El factor extrínseco de alteración primordial es la contaminación atmosférica, principalmente óxidos de azufre y humos, en ambiente húmedo. De ambos factores, piedra porosa de naturaleza carbonatada y medio ambiente ácido, puede deducirse que el principal mecanismo de alteración es el ataque químico y se ha encontrado que los indicadores de alteración más importantes son los depósitos y las arenizaciones. En una valoración a grosso modo puede decirse que la piedra de uso estructural se encuentra bien conservada en su mayor parte, y la ornamental degradada en un 80 %. La mitad de las cresterías se encuentran en estado de ruina y un 20 % de los remates han sido retirados o habrán de serlo próximamenteThe lithotype mainly used in the construction of the Cathedral of Seville is the calcarenite from Puerto de Santa f\/laria followed by the limestone from Espera. The primordial extrinsecal factor of deterioration is the atmospherical contamination, mainly sulphur oxides and smoke, within a humid environment. From both factors, the porose stone of a carbonated nature and the acid environment, we can deduce that the principal mechanism of deterioration is the chemical attack; the most important indicators of deterioration that have been found are the deposits and arenizations. In a "grosso modo" valoration we can say that the stone of structural employment is well conserved in its majority while the ornamental stone is degraded at 80 %. Half the cresting is in a state of ruin and 20 % of the tips have been removed or will have to be in the near future

Morfología macroscópica de alteración acelerada de algunos materiales pétreos de monumentos de Andalucía/España

Varios litotipos utilizados en diversos monumentos andaluces han sido sometidos a experiencias de laboratorio de cristalización de sales y en atmósferas controladas. Los indicadores de alteración que aparecen son justificados desde el punto de vista del tipo de experiencia y del litotipo, y comparados con aquéllos encontrados en los monumentos. De especial significación es la experiencia de capilaridad con ventilación forzada, de diseño sencillo y original, con la que se reproducen las tipleas descamaciones de los mármoles de la Catedral de Cádiz.Several lithotypes used in diverse Andalusian monuments have undergone laboratory experiments of salt crystallization and within controlled environments. The indicators of deterioration that appear are justified from the point of view of the type of experiment and the lithotype, and compared with those found in the monuments. The capillarity with forced ventilation experiment, with an original and simple design, is of special signification. With wich the typical desquamations in the marbles of the Cathedral of Cádiz are reproduced

Morfología macroscópica de alteración de la piedra de la Catedral de Almería/España

Los vientos reinantes en la zona, asociados a una importante humedad ascendente, son los principales factores naturales de alteración que afectan a la Catedral de Almería. Pueden señalarse como factores antropogénicos de alteración ciertas desafortunadas labores de mantenimiento llevadas a cabo, así como, aunque con carácter episódico, los bombardeos y ametrallamientos sufridos por el edificio durante la guerra civil. El único litotipo empleado en la construcción es una caliza dolomítica de elevada porosidad procedente de canteras próximas a la ciudad. Los principales mecanismos de alteración son los de incremento de volumen en capilares e intersticios, ligados a la presencia de sales, y los de disolución, dada la solubilidad de las sales de magnesio de constitución, que pueden producir la desdolomitización de la piedra. Esto conduce a unos indicadores de alteración con una morfología típica consistente en huecos en todas sus manifestaciones: picados, alveolizaciones y cavernas. La mayor degradación se da en las partes altas y bajas del edificio, allí donde los factores viento y humedad, respectivamente, son más intensos. La alteración antropogénica también toma, casi irónicamente, la forma de huecos, como los impactos de balas y obuses de la fachada Sur y las regolas practicadas para cables eléctricos en todo el edificio. Diversas restauraciones han introducido tensiones en los materiales que han conducido a decohesiones en diversos grados (desagregaciones, disgregaciones y arenizaciones) en el interior del templo y en el claustro. El edificio se encuentra en un estado de alteración de cierta significación que esencialmente afecta a la estética del mismo. La velocidad del proceso degradativo observada en ciertas áreas del mismo, en particular en las restauradas, reclama actuaciones urgentes para su mantenimiento.The prevailing winds in the área, associated with an important rising damp are the main natural factors of deterioration that affect the Cathedral of Almería. Certain unfortunate maintenance Jobs carried out as well as the bombardments and machine-gunning on the building during the Civil War can be indicated as anthropogenical factors of deterioration. The only lithotype used in the construction is a dolomitic limestone of high porosity from quarries near the city. The increase in volume in capillaries and interstices, related whith the presence of salts, and the dissolution, due to the great solubility of the natural magnesium salts which can produce dedolomitization of the stone, are the main deterioration mechanisms. This leads to indicators of deterioration with a typical morphology consisting of openings in all its manifestations (pitting, alveolar erosions and craters) especially on the high and low parts of the building where the wind and humidity, respectively, are more intense. The anthropogenical deterioration also has the shape of openings, such as the impact of bullets and obuses on the Southern fagade and the grooves made for electric cables throughout the building. Diverse restorations have introduced tensions in the materials which have led to decohesions at different degrees (disaggregations, disintegrations and grain disgregations) in the interior of the temple and cloister

Main Variables Affecting a Chemical-Enzymatic Method to Obtain Protein and Amino Acids from Resistant Microalgae

he development of microalgae uses requires further investigation in cell disruption alternatives to reduce the costs associated to this processing stage. This study aimed to evaluate the main variables affecting an extraction method to obtain protein and amino acids from microalgae. The method was based on a sequential alkaline-enzymatic process, with separate extractions and noncontrolled pH, and was applied to fresh biomass of a resistant species. The processed microalgae were composed of a consortium with Nannochloropsis sp. as predominant species. After the optimization of the pH of the alkaline reaction, the effect of the time of the alkaline reaction (30-120min), the time (30-120min) and temperature (40-60 degrees C) of the enzymatic reaction, and the biomass concentration (50-150mgml(-1)), on the extraction yields of protein and free amino nitrogen (FAN) and on the final concentration of protein in the extract, was studied using a response surface methodology. Even though all the variables and some interactions among them had a significant effect, the biomass concentration was the most important factor affecting the overall process. The results showed relevant information about the different options in order to maximize not only the response variables individually but also different combinations of them. Assays with optimized values reached maximum yields of 80.3% and 1.07% of protein (% of total protein) and FAN (% of total biomass), respectively, and a protein concentration in the extract of 15.2mgml(-1). The study provided the essential information of an alternative approach to obtain protein and amino acids from fresh biomass of resistant microalgae with a high yield, also opening perspectives for further research in particular aspects

Movements and capture-recapture data analysis of the vesper rat (Nyctomys sumichrasti : Rodentia, Muridae) in a tropical forest in northeastern Oaxaca, Mexico.

In order to explain the population demography of the Vesper Rat (Nyctomys sumichrasti) and with regarding to an estimate of population size and survival rates, as well as possible differences in the movements distances between males and females, we analyzed capture-recapture data of this species from a trapping effort of 455 trap-nights and a total of 157 captures of 36 individuals which were livetraped at 3 trap heights: 3-9 m above ground (low canopy), 9-15 m (medium canopy) and the highest part of the canopy, 15-21.5 m. Due to differences between age categories in sample size, the analysis of capture-recapture histories was restricted to adult individuals. The sample of 29 adult individuals included 12 females (8 singletons and 4 captured in the complete study) and 17 males (5 singletons and 12 captured in the complete study); which represents a sex-ratio of 1:1.41, which did not differ statistically from 1:1. The capture-recapture histories were analyzed using the Cormack-Jolly-Seber model, where the best model maintains the survival constant and equal between sexes, and capture probability is constant through time, but differs between sexes. The survival probability was 0.8287, while the capture probability was 0.874 for males and 0.5733 for females. Estimated population size included 19 males and 21 females. The average distance travelled by females was 34.86 m (standard deviation 5.92) with extreme values of 20.1 to 60.32, whereas for males was 35.42 m (standard deviation 18.27), with extreme values of 10.3 to 75.1 m

Mapping the potential distribution of frozen ground in Tucarroya (Monte Perdido Massif, the Pyrenees)

Producción CientíficaEste trabajo describe la metodología utilizada para cartografiar los suelos potencialmente helados en el valle de Tucarroya, en el Parque Nacional de Ordesa. Para cartografiar las formas asociadas a la presencia de hielo se combinó trabajo de campo, datos térmicos procedentes de sensores automáticos de temperatura del suelo y mediciones de la base del manto de nieve (BTS), así como variables predictivas obtenidas de un Modelo Digital de Elevaciones (MDE). La cartografía diferencia cuatro ambientes, suelo no congelado con actividad de la helada, suelos helados estacionales, permafrost posible y permafrost probable. El mapa revela una extensión del permafrost muy limitada, con escasez de formas asociadas. Solo se ha detectado por encima de los 2700 m de altitud en ambientes topográficos favorables, pendientessuaves y protegidos de la radiación solar. Los suelos helados estacionales son los ambientes más comunes y se desarrollan por encima de los 2500 m s.n.m., mientras los suelos no congelados,pero con heladas solo están presentes entre los 2570 y los 2750 m de altitud en laderas que reciben elevada radiación solarMinisterio de Economía, Industria y Competitividad - Fondo Europeo de Desarrollo Regional (projects CGL2015-68144-R / CGL2017-82216-R)Geoparque de Sobrarbe (project R- ADM15/57