Search results for "Spectral"
showing 10 items of 3116 documents
Accelerated Light-Induced Defect Transformation Study of Elkem Solar Grade Silicon
2012
AbstractSolar cells made of silicon feedstock from a metallurgical route must qualify not only the initial efficiency, but must also be comparable to the solar cells made from reference polysilicon on the spectral response after light induced degradation. A detailed comparative study of light induced defects and its impact on cell performance is necessary for both materials. We have studied accelerated light induced degradation (ALID) defect transformation for Elkem Solar Silicon and polysilicon solar cells by selecting wafers from different positions from respective silicon bricks. Active boron-oxygen complexes and iron ions in multicrystalline silicon solar cells have been analyzed, and t…
Laboratory measurements and astronomical search for the HSO radical
2016
[Context] Despite the fact that many sulfur-bearing molecules, ranging from simple diatomic species up to astronomical complex molecules, have been detected in the interstellar medium, the sulfur chemistry in space is largely unknown and a depletion in the abundance of S-containing species has been observed in the cold, dense interstellar medium. The chemical form of the missing sulfur has yet to be identified.
Dependence of the emission properties of the germanium lone pair center on Ge doping of silica
2011
We present an experimental investigation regarding the changes induced by the Ge doping level on the emission profile of the germanium lone pair center (GLPC) in Ge doped silica. The investigated samples have been produced by the sol-gel method and by plasma-activated chemical vapor deposition and have doping levels up to 20% by weight. The recorded photoluminescence spectra show that the GLPC emission profile is the same when the Ge content is lower than ∼ 1% by weight, whereas it changes for higher doping levels. We have also performed Raman scattering measurements that show the decrease of the D1 Raman band at 490 cm( - 1) when the Ge content is higher than 1% by weight. The data suggest…
<title>Micro-Raman scattering and infrared spectra of hemoglobin</title>
2008
Confocal micro-Raman and FT-IR spectroscopies have been used for detection of radiation influence of hemoglobin of patients examined by radio-isotopes diagnosis (Tc99m). After irradiation we observed some little changes of the Raman scattering bands which connected with out of plane porphyrine bending vibrations, also we observed additional band due to methemoglobin. Radiation of blood lead to the transition from hemoglobin (Fe2+) to methemoglobin (Fe3+) with a delocalization of iron from porphyrine plane. It was shown that FT-IR spectra indicate the radiation effects on hemoglobin.© (2008) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is per…
Determination of reflectance spectra model of skin phototypes V
2012
In dermatology, skin is assessed for its response to UV light and is categorised under the Fitzpatrick skin type (FST). The FST is commonly applied as a predictor of skin cancer. The FST classification however is subjective. To enable an objective assessment, a pattern model of skin colour taken from normal subjects is required. In this paper, a model for skin phototype (SPT) V is developed and presented. We conducted an observational study involving 41 participants with FST V. The study analysed the reflectance spectra of facultative skin and constitutive skin which was captured using spectrophotometer and multispectral camera. Using piecewise linear regression, we modelled the reflectance…
A sharp estimate for Neumann eigenvalues of the Laplace-Beltrami operator for domains in a hemisphere
2018
Here, we prove an isoperimetric inequality for the harmonic mean of the first [Formula: see text] non-trivial Neumann eigenvalues of the Laplace–Beltrami operator for domains contained in a hemisphere of [Formula: see text].
Utilidad clínica del Índice Biespectral (BIS) para la detección de isquemia cerebral durante endarterectomía carotídea
2015
La monitorización intraoperatoria de isquemia cerebral para la inserción de un shunt durante la cirugía de carótida es controvertida. El índice Biespectral (BIS) derivado del EEG puede resultar útil en el diagnóstico de isquemia cerebral intraoperatoria como han sugerido diversas publicaciones de casos clínicos. Los objetivos fueron 1) investigar los cambios del BIS en pacientes que presentaron déficits neurológicos y sin déficits neurológicos durante la cirugía carotídea bajo anestesia regional. 2) Evaluar la sensibilidad y especificidad de los cambios del BIS durante el clampaje carotídeo en relación a los pacientes con shunt en la endarterectomía carotídea en pacientes despiertos. 3) Ide…
Rapid Quantification of Microalgae Growth with Hyperspectral Camera and Vegetation Indices
2021
Spectral cameras are traditionally used in remote sensing of microalgae, but increasingly also in laboratory-scale applications, to study and monitor algae biomass in cultures. Practical and cost-efficient protocols for collecting and analyzing hyperspectral data are currently needed. The purpose of this study was to test a commercial, easy-to-use hyperspectral camera to monitor the growth of different algae strains in liquid samples. Indices calculated from wavebands from transmission imaging were compared against algae abundance and wet biomass obtained from an electronic cell counter, chlorophyll a concentration, and chlorophyll fluorescence. A ratio of selected wavebands containing near…
Assessment of microalgae species, biomass and distribution from spectral images using a convolution neural network
2021
Artikkeliin "Assessment of microalgae species, biomass and distribution from spectral images using a convolution neural network" liittyvä aineisto koostuu seuraavista osista: 1.Transmittanssi-hyperspektrikuvat levänäytteistä kuvattuina 24-kuoppalevyllä 2.Biomassamääritykset elektronisella solulaskurilla 3.Opetus- ja validointiaineisto konvoluutioneuroverkolle 4.Testiaineisto konvoluutioneuroverkolle 5.Opetus-, validointi- ja testiaineiston käsittelyyn käytetty Python koodi 6.Seitsemään eri malliin käytetty Python koodi ja mallit itsessään The data and code related to the article "Assessment of microalgae species, biomass and distribution from spectral images using a convolution neural netwo…
Analysis of the performance of the TES algorithm over urban areas
2014
International audience; The temperature and emissivity separation (TES) algorithm is used to retrieve the land surface emissivity (LSE) and land surface temperature (LST) values from multispectral thermal infrared sensors. In this paper, we analyze the performance of this methodology over urban areas, which are characterized by a large number of different surface materials, a variability in the lowest layer of the atmospheric profiles, and a 3-D structure. These specificities induce errors in the LSE and LST retrieval, which should be quantified. With this aim, the efficiency of the TES algorithm over urban materials, the atmospheric correction, and the impact of the 3-D architecture of urb…