Assessment of the SBAC atmospheric correction technique applied to Landsat 8-TIRS from ground LST measurements in the Barrax test site

La peculiar estructura y propiedades físico-químicas del silicio poroso nanoestructurado ha estimulado el uso de este material en una amplia variedad de aplicaciones. En el campo de la optoelectrónica, la posibilidad de producir estructuras multicapa en las que cada una de las capas tiene propiedades ópticas particulares, permite la fabricación de filtros ópticos interferenciales con un comportamiento predefinido. En este trabajo se han utilizado estructuras multicapa de silicio poroso para filtrar la luz incidente sobre un sustrato fotosensible de silicio con la intención de modular su respuesta espectral. El comportamiento óptico del filtro de silicio poroso fue simulado antes de su fabricación, y las medidas ópticas demostraron un buen acuerdo entre el comportamiento del filtro obtenido y las predicciones teóricas. Mediciones de fotocorriente han demostrado que los filtros de silicio poroso han reducido el rango espectral de fotosensibilidad del silicio, de los >750 nm originales a unos 150 nm. Filtros con distintos diseños han permitido no sólo estrechar la banda espectral de sensibilidad del detector pancromático de Si, sino también sintonizarla a lo lago de todo el rango visible. El silicio poroso nanoestructurado es compatible con las técnicas convencionales de fabricación microelectrónica, lo que hace posible incorporar estos filtros interferenciales sobre una amplia variedad de sensores y fotodiodos pancromáticos VIS, NIR o SWIR convencionales. Los resultados presentados en este trabajo demuestran que los filtros interferenciales de silicio poroso reestructurado resultan muy prometedores para el desarrollo de sensores multi- e hiperespectrales de bajo costeThe particular structure and physico-chemical properties of nanostructured porous silicon has stimulated the use of this material in many different applications. In the field of optoelectronics, the possibility of fabricating multilayer stacks where each individual layer has different optical properties allows the formation of optical interference filters with a predesigned behavior. In the present work, nanostructured porous silicon interference multilayer structures have been used to filter incident light reaching a Si photosensitive wafer in order to tailor its spectral response. The optical behavior of the porous silicon filters was simulated prior to their fabrication, and optical measurements showed good agreement between the simulated and experimental spectra. Photocurrent measurements have shown that the porous silicon filters narrowed the spectral responsitivity of silicon, from the original value of >750 nm down to around 150 nm. Different filter designs allowed to not only narrowen, but also tune the Si panchromatic sensitivity along the whole visible range. Porous silicon is compatible with standard microelectronic fabrication processes, making it possible to incorporate these interference filters onto a wide variety of conventional panchromatic VIS, NIR or SWIR broad band sensors. These results show that nanostructured silicon interference filters are a promising tool for developing cost-effective multi- and hyperspectral narrowband sensor

The critical coupling likelihood method: a new approach for seamless integration of environmental and operating conditions of gravitational wave detectors into gravitational wave searches

Any search effort for gravitational waves (GWs) using interferometric detectors like LIGO needs to be able to identify if and when noise couples into the detector’s output signal. The critical coupling likelihood (CCL) method has been developed to characterize potential noise coupling and in the future aid GW search efforts. By testing two hypotheses about pairs of channels, CCL is able to identify undesirable coupled instrumental noise from potential GW candidates. Our preliminary results show that CCL can associate up to ∼80% of observed artifacts with SNR ⩾ 8 with local noise sources, while reducing the duty cycle of the instrument by ≲ 15%. An approach like CCL will become increasingly important as GW research moves into the advanced LIGO era, going from the first GW detection to GW astronomy

Sentinel 2 as a visualization tool of the historical urban growth of cities

La observación multiespectral de las ciudades desde el espacio es una herramienta sumamente valiosa para conocer la situación actual de las mismas. Sin embargo, estas mismas imágenes pueden aportar información también sobre la historia pasada de las mismas. En este trabajo se propone el procesado de imágenes Sentinel 2 para visualizar el crecimiento urbano de las ciudades a lo largo del tiempo. En concreto, se ha usado la combinación de bandas 12,11,4 y 12,8,3 para obtener imágenes en falso color que resaltan intensamente los diferentes materiales de techado utilizados en el tiempo. Esta combinación de bandas infrarrojas y roja resultan muy útiles para diferenciar materiales como la teja, el cemento o los materiales sintéticos impermeabilizantes, permitiendo diferenciar a simple vista los distintos barrios que forman la ciudad en función de su época de construcción, dando una visión global de las fases de crecimiento de la ciudad. Este tipo de imágenes resultan muy intuitivas para los estudiantes, convirtiéndose en una valiosa herramienta didáctica y de divulgaciónMultispectral observation of cities from space is a key tool for understanding their current state. Moreover, this kind of imagery may provide insight into the past history of cities. This work proposes the process of Sentinel 2 images for visualizing urban growth of cities in time. In particular, RGB composite of bands 12,11,4 and 12,8,3 provide false color images that highlight the different roofing materials used through history. This particular combination of infrared and red bands are very useful for differentiating materials such as red tile, cement or sinthetic impermeabilization materials, allowing to visually different phases of city growth. These images are very intuitive for students and non professionals, becoming a valuable tool for history teaching and divulgatio

Photodynamic therapy as adjunctive therapy for morpheaform basal cell carcinoma

The authors decided to evaluate the possible use of methyl-aminolevulinate photodynamic therapy (MAL-PDT) as adjunctive therapy for morpheaform basal cell carcinoma prior to standard surgical excision in order to reduce tumor size and volume and to facilitate surgical treatment. It was observed that MAL-PDT may be an option as an adjunctive therapy prior to standard surgical excision of morpheaform basal cell carcinoma, leading to less invasive surger

Coupled quintessence and vacuum decay

We discuss observational consequences of a class of cosmological models characterized by the dilution of pressureless matter attenuated with respect to the usual $a^{-3}$ scaling due to the decay of vacuum energy. We carry out a joint statistical analysis of observational data from the new \emph{gold} sample of 182 SNe Ia, recent estimates of the CMB shift parameter, and BAO measurements from the SDSS to show that such models favor the decay of vacuum only into the dark matter sector, and that the separately conserved baryons cannot be neglected. In order to explore ways to more fundamentally motivated models, we also derive a coupled scalar field version for this general class of vacuum decay scenarios.Comment: 6 pages, 3 figures, LaTe

Influence of wall material concentration and core-to-wall material ratio on the encapsulation of pomegranate seed oil by complex coacervation.

Pomegranate seed oil (PSO) is rich in bioactive compounds, such as conjugated linolenic acids (CLnA). Encapsulation is a packing technology that enables the application of highly oxidizable oils in food matrices. Technological properties of particles produced by this method are highly influenced by wall material (WM) concentration and core:WM ratio. The objective of this study was to evaluate the effects of the WM concentration and the core:WM ratio in the microencapsulation of PSO by complex coacervation.SLACA, 12. De 4 a 7 de Novembro de 2017. Ref. 71235

Optical microtopographic inspection of asphalt pavement surfaces

Microtopographic and rugometric characterization of surfaces is routinely and effectively performed non-invasively by a number of different optical methods. Rough surfaces are also inspected using optical profilometers and microtopographer. The characterization of road asphalt pavement surfaces produced in different ways and compositions is fundamental for economical and safety reasons. Having complex structures, including topographically with different ranges of form error and roughness, the inspection of asphalt pavement surfaces is difficult to perform non-invasively. In this communication we will report on the optical non-contact rugometric characterization of the surface of different types of road pavements performed at the Microtopography Laboratory of the Physics Department of the University of Minho.This work was partially financed project PEst-OE/ECI/UI4047/2014 supported by Portuguese Foundation for Science and Technology.info:eu-repo/semantics/publishedVersio

Spatio-temporal analysis of the degradation of salts-affected soils in the lacustre system of Texcoco Valley (Mexico)

El Valle de Texcoco, uno de los cinco lagos que conformaban el gran lago de Tenochticlan en el periodo colonial de la ciudad de México (año 1520), es hoy en día una de las regiones del planeta con mayor superficie de suelos afectados por salinidad extrema (>10 000 ha). La salinidad de los suelos es un grave problema en regiones áridas o semiáridas, ya que afecta a la productividad agrícola y la calidad de las aguas, con graves consecuencias socioeconómicas, como la desertificación y migración a las ciudades. Además, las sales se disuelven con facilidad en el suelo, por lo que se requieren herramientas de monitorización precisas que permitan evaluar la alta variabilidad espacio-temporal de los suelos afectados por sales. Este trabajo tiene como objetivo evaluar el estado de los suelos afectados por salinidad en el valle de Texcoco, así como los cambios de uso de suelo acontecidos en los últimos 30 años. Para ello se emplearán técnicas de GIS, imágenes de satélite Landsat desde la década de los 80 hasta la actualidad (1985-2015), y radiómetros de campo para identificar las firmas espectrales de los suelos en condiciones de laboratorio. Una vez procesadas las imágenes de satélite Landsat (corrección radiométrica y atmosférica, y aplicación de filtros), se identificaron diferentes cubiertas o usos de suelo: agua, vegetación semi-natural, tierras de cultivo, suelos sin vegetación y suelos salinos. Se calcularon diferentes índices radiométricos para distinguir la vegetación de las tierras de cultivo y de los suelos salinos. El sistema de clasificación no supervisada mostró cambios de uso de la tierra en el 80% de la superficie en 30 años. Disminuye el agua potable y las tierras agrícolas e incrementan en más de un 20% los suelos degradados por sales o de uso urbano. Se trata de una región con riesgo extremo por pérdida y degradación de las tierras de cultivo por efecto de la salinidadThe Valley of Texcoco, one of the five lakes that formed the great lake of Tenochticlan in the colonial period of Mexico City (year 1520), is today one of the regions with the largest surface area of soils affected by extreme salinity (>10 000 ha). The salinity of soil is a serious problem in arid or semi-arid regions. It affects to agricultural productivity and water quality, with serious socioeconomic consequences, such as desertification and migration of the rural populations to the cities. So, salts dissolve easily in the soil, so precise monitoring tools are necessary to evaluate the high spatiotemporal variability by salts-affected soils. The aim is to evaluate the state of salts-affected soils in the Texcoco Valley, as well as the land use changes in the last 30 years. GIS, Landsat satellite images from the 1980s to the present (1985-2015), and field radiometers will be used to identify the spectral signatures of salts-affected soils under laboratory conditions. Once processed the multispectral images (radiometric and atmospheric correction, and filters application), different land uses were identified: water, semi-natural vegetation, agricultural lands, soil without vegetation and saline soils. Different radiometric indices were used to differentiate vegetation from agricultural and saline soils. The unsupervised classification system showed changes at 80% of the surface in land use in 30 years. Clear water and agricultural land decreased and increased at 20% the soils degraded by salts or urban use. It is a region with extreme risk due to the salts-affected soil

Porous silicon bragg reflector and 2D gold-polymer nanograting: a route towards a hybrid optoplasmonic platform

Photonic and plasmonic systems have been intensively studied as an effective means to modify and enhance the electromagnetic field. In recent years hybrid plasmonic–photonic systems have been investigated as a promising solution for enhancing light-matter interaction. In the present work we present a hybrid structure obtained by growing a plasmonic 2D nanograting on top of a porous silicon distributed Bragg reflector. Particular attention has been devoted to the morphological characterization of these systems. Electron microscopy images allowed us to determine the geometrical parameters of the structure. The matching of the optical response of both components has been studied. Results indicate an interaction between the plasmonic and the photonic parts of the system, which results in a localization of the electric field profile

The Critical Coupling Likelihood Method: A new approach for seamless integration of environmental and operating conditions of gravitational wave detectors into gravitational wave searches

Any search effort for gravitational waves (GW) using interferometric detectors like LIGO needs to be able to identify if and when noise is coupling into the detector's output signal. The Critical Coupling Likelihood (CCL) method has been developed to characterize potential noise coupling and in the future aid GW search efforts. By testing two hypotheses about pairs of channels, CCL is able to identify undesirable coupled instrumental noise from potential GW candidates. Our preliminary results show that CCL can associate up to $\sim 80$ of observed artifacts with $SNR \geq 8$, to local noise sources, while reducing the duty cycle of the instrument by $\lesssim 15$. An approach like CCL will become increasingly important as GW research moves into the Advanced LIGO era, going from the first GW detection to GW astronomy.Comment: submitted CQ