Broadband telecom transparency of semiconductor-coated metal nanowires: more transparent than glass

Metallic nanowires (NW) coated with a high permittivity dielectric are proposed as means to strongly reduce the light scattering of the conducting NW, rendering them transparent at infrared wavelengths of interest in telecommunications. Based on a simple, universal law derived from electrostatics arguments, we find appropriate parameters to reduce the scattering efficiency of hybrid metal-dielectric NW by up to three orders of magnitude as compared with the scattering efficiency of the homogeneous metallic NW. We show that metal@dielectric structures are much more robust against fabrication imperfections than analogous dielectric@metal ones. The bandwidth of the transparent region entirely covers the near IR telecommunications range. Although this effect is optimum at normal incidence and for a given polarization, rigorous theoretical and numerical calculations reveal that transparency is robust against changes in polarization and angle of incidence, and also holds for relatively dense periodic or random arrangements. A wealth of applications based on metal-NWs may benefit from such invisibility

On the occurrence of Zenopsis conchifer (Lowe, 1852) (Osteichthyes, Zeidae) in the Mediterranean Sea

Sobre la presència de Zenopsis conchifer (Lowe, 1852) (Osteichthyes, Zeidae) al mar Mediterrani S’informa de la captura de quatre exemplars de Zenopsis conchifer, espècie que va ser citada per primera vegada al Mediterrani l’any 2007, a las costes de la península Ibèrica. Un dels exemplars va ser capturat prop de l’estret de Gibraltar, per la qual cosa probablement es tractava d’un individu errant. Malgrat aquestes captures no hi ha evidència de l’existència d’una població estable, raó per la qual l’espècie ha de continuar sent considerada com a exòtica al Mediterrani.The capture of four specimens of Silvery John Dory (Zenopsis conchifer),a species recorded in the Mediterranean Sea for the first time in 2006, is reported from the Iberian coast (western Mediterranean). One of the specimens was caught near the Strait of Gibraltar and is probably a vagrant. Despite these catches, there is no evidence of a self–sustaining population, so this species should be considered as alien in the Mediterranean.Sobre la presencia de Zenopsis conchifer (Lowe, 1852) (Osteichthyes, Zeidae) in el Mar Mediterráneo Se informa de la captura de cuatro ejemplares de Zenopsis conchifer, especie cuya primera cita en el Mediterráneo data del año 2007, en las costas de la península ibérica. Uno de los ejemplares fue capturado cerca del estrecho de Gibraltar, por lo que probablemente se trataría de un individuo errante. A pesar de estas capturas, no hay evidencia de la existencia de una población

Effect of haptic geometry in C-loop intraocular lenses on optical quality

The biomechanical stability of intraocular lenses (IOLs) must achieve high-quality optical performance and clinical outcomes after cataract surgery. For this reason, the quality and performance features of the IOLs should be previously analysed following the Standard ISO 11979-2 and ISO 11979-3. The ISO 11979-3 tries to reproduce the behaviour of the IOL in the capsular bag by compressing the lens between two clamps. With this test, it has been demonstrated that the haptic design is a crucial factor to obtain biomechanical stability. Hence, the main goal of this study was to design an aberration-free aspheric IOL and to study the influence of haptic geometry on the optical quality. For that purpose, 5 hydrophobic IOLs with different haptic design were manufactured and their biomechanical stability was compared experimentally and numerically. The IOLs were classified as stiff and flexible designs depending on their haptic geometry. The biomechanical response was measured by means of the compression force, the axial displacement, the angle of contact or contact area, the decentration, the tilt and the strain energy. The results suggest that in vitro and in silico compression tests present similar responses for the IOLs analysed. Furthermore, the flexible IOL designs presented better biomechanical stability than stiff designs. These results were correlated with the optical performance, where the optical quality decreases with worst biomechanical stability. This numerical methodology provides an indisputable advance regarding IOL designs, leading to reduce costs by exploring a feasible space of solutions during the product design process and prior to manufacturing

Generation of a porous scaffold with a starting composition in the CaO-SiO2-MgO-P2O5 system in a simulated physiological environment

Magnesium-based ceramics are involved in orthopedic applications such as bone scaffolds or implant coatings. They provide structural support to cells for bone ingrowth, but highly porous matrices cannot resist severe mechanical stress during implantation. In this study, the laser floating zone (LFZ) technique is used to prepare a dense crystalline material with composition in the CaO-SiO2-MgO-P2O5 system. This material, under physiological conditions, is able to generate a porous scaffold controlled by the dissolution of the MgO phase, meeting the mechanical advantages of a dense material and the biological features of a porous scaffold. FESEM (Field emission scanning electron microscopy), XRD (X-ray Diffraction), EDS (Energy Dispersive X-rays spectroscopy), and ICP ((Inductively Coupled Plasma) analysis were carried out in order to characterize the samples before and after immersion in simulated body fluid (SBF)

Efecto de la procedencia en la supervivencia de plántulas de Pinus canariensis Sm. en medio árido

Survival and height growth of two-year seedlings of Canary Islands pine (Pinus canariensis Sm.) were evaluated in a field trial, eight months after plantation. The trial was located at Betancuria (Fuerteventura island, Canary archipelago), under extremely arid conditions. Plants were rised from seeds collected at nine natural stands of the species, selected by their climatic traits. Correlation between mean survival rate and mean annual rainfall at the population level was –0.93. Population was not significant on survival, but a significant effect was found after grouping populations into two climatic groups, xeric and mesic. The survival rate of the xeric group (annual rainfall ranging from 300 to 450 mm) was 60 %, higher than that of the mesic group (500-600 mm), which attained 45 %. No significant relationship was observed between plant height and survival.La supervivencia y el crecimiento en altura se evaluaron en plantas de dos años de pino canario (Pinus canariensis Sm.) ocho meses después de la plantación. El sitio de ensayo se localizó en Betancuria (Fuerteventura) bajo condiciones de gran aridez. Las plantas procedían de semilla de nueve poblaciones naturales de la especie (una de Tenerife, una de El Hierro, tres de La Palma y cuatro de Gran Canaria), seleccionadas en función de sus características climáticas. La correlación entre la supervivencia media por población y la precipitación media anual en origen fue –0,93. La población no fue estadísticamente significativa en la supervivencia, pero se puso de manifiesto un efecto significativo tras dividir las poblaciones en dos grupos climáticos, seco y húmedo. El porcentaje de supervivencia en el primer grupo (precipitación anual de 300-450 mm) fue del 60 %, mientras que el segundo (500-600 mm) sólo alcanzó un valor del 45 %. No se detectó ninguna relación significativa entre la altura de las plantas y su supervivencia

Determination of field capacity and yield mapping in olive harvesting using remote data acquisition

Sensors, communication systems and geo-reference units are required to achieve an optimized management of agricultural inputs with respect to the economic and environmental aspects of olive groves. In this study, three commercial olive harvesters were tracked in Spain and Chile using remote and autonomous equipment to determine their time efficiency and field capacity. An experimental methodology for analyzing the data to determine the field capacity and efficiency is proposed, which, along with a conventional methodology, was used to analyze the data to determine field capacity and efficiency. The results of both methodologies are compared to validate the suitability of the experimental methodology. Furthermore, a yield monitor was developed and evaluate using one of the tested olive harvesters. The results show that yield monitoring of olives is possible, but further research is needed to archieve a more reliable methodology

Remote sensing detection of nutrient uptake in vineyards using narrow-band hyperspectral imagery

This manuscript delves further into the assessment of narrow-band vegetation indices derived from hyperspectral imagery acquired at 1 m spatial resolution with the Compact Airborne Spectrographic Imager (CASI). Narrow-band indices proposed in this study were assessed as indicators of biochemical and structural parameters in Vitis vinifera L., observing their relationships with foliar variables such as N, P, K, Ca, Fe, Mg and chlorophyll a+b concentration (Ca+b). Hyperspectral indices were assessed to study their capability for vegetation condition monitoring as a function of fertilization treatments applied (basically extracts of Ascophyllum nodosum seaweed and chelates), showing associations with field variables. Narrow-band vegetation indices displayed sensitivity to vineyard growth and condition as a function of seaweed fertilization and other supplementary mineral correctors, such as chelates. This work shows the interest of using new narrow-band hyperspectral remote sensing indices for vineyard monitoring due to their potential to indicate physiological condition.

Development of a Telemetry and Yield-Mapping System of Olive Harvester

Sensors, communication systems and geo-reference units are required to achieve an optimized management of agricultural inputs with respect to the economic and environmental aspects of olive groves. In this study, three commercial olive harvesters were tracked during two harvesting seasons in Spain and Chile using remote and autonomous equipment that was developed to determine their time efficiency and effective based on canopy shaking for fruit detachment. These harvesters work in intensive/high-density (HD) and super-high-density (SHD) olive orchards. A GNSS (Global Navigation Satellite System) and GSM (Global System for Mobile Communications) device was installed to track these harvesters. The GNSS receiver did not affect the driver’s work schedule. Time elements methodology was adapted to the remote data acquisition system. The effective field capacity and field efficiency were investigated. In addition, the field shape, row length, angle between headland alley and row, and row alley width were measured to determinate the optimum orchard design parameters value. The SHD olive harvester showed significant lower effective field capacity values when alley width was less than 4 m. In addition, a yield monitor was developed and installed on a traditional olive harvester to obtain a yield map from the harvested area. The hedge straddle harvester stood out for its highly effective field capacity; nevertheless, a higher field efficiency was provided by a non-integral lateral canopy shaker. All of the measured orchard parameters have influenced machinery yields, whether effective field capacity or field efficiency. A saving of 40% in effective field capacity was achieved with a reduction from 4 m or higher to 3.5 m in alley width for SHD olive harvester. A yield map was plotted using data that were acquired by a yield monitor, reflecting the yield gradient in spite of the larger differences between tree yield

LA DOMESTICACIÓN DE PLANTAS EN MÉXICO: COMPARACIÓN DE LA FORMA CULTIVADA Y SILVESTRE DE BYRSONIMA CRASSIFOLIA (MALPIGHIACEAE)

Domesticated plants show characteristicsknown as domestication syndrome, whichenables better utilization of the plants byhumans. Plant domestication has been studied mainly in herbaceous annuals. In thiswork, samples of Byrsonima crassifoliatrees–changunga, the wild form, and nanche,the cultivated form–were taken from theregion of Uruapan, Mexico. The objective ofthis work was to identify genetic differencesby AFLP molecular markers between thesetwo forms. Analysis showed that both wild and cultivated forms of B. crassifolia aregenetically very close to each other. Fruitcharacteristics of human-interest were compared, and some differences were foundbetween the two forms, e.g., in pH, sweetness, mineral content and size. The AFLPanalysis groups together the two forms ofthe tree with a high degree of similarity.The fruits are distinguished phenotypicallyfrom one another, but not at the molecularlevel. Selection pressure to supply themarket may threaten the diversity present inthese populations of plants, which could bea model for the screening of genes involvedin traits such as sweetness and fruit size inaddition to the process of domesticationitself. It is recommended that collections bemade for germoplasm gene banks and alsothat in situ conservation be promoted.Las plantas domesticadas presentan unaserie de características conocidas comosíndrome de domesticación. Esto permiteun mejor aprovechamiento de las mismaspor parte de los humanos y ha sido estudiadaprincipalmente en plantas anuales herbá-ceas. En este trabajo se hizo un muestreo deárboles silvestres (changunga) y cultivados(nanche) de Byrsonima crassifolia en laregión de Uruapan, México. El objetivo fuebuscar diferencias genéticas mediante marcadores moleculares por medio de la técnicade AFLP entre las dos formas de la especie,encontrándose que tanto los silvestres comolos cultivados están genéticamente muycercanos entre sí. También se compararoncaracterísticas de los frutos como pH, dulzorde los frutos, tamaño y contenido mineralencontrándose diferencias en las tres primeras. El análisis de AFLP’s agrupa juntosa las dos formas del árbol con alto gradode similitud. Fenotípicamente los frutos sedistinguen entre sí, pero no a nivel molecular. La presión de selección para surtir almercado puede poner en riesgo la diversidadpresente en estas poblaciones que se proponepodrían ser un modelo para la búsqueda degenes que intervienen en característicascomo dulzor y tamaño de fruto además delproceso de domesticación en sí mismo. Serecomienda hacer colectas para los bancosde germoplasma además de tratar de promover la conservación in situ