Search results for " resolution"
showing 10 items of 1159 documents
Estimating chlorophyll content of crops from hyperspectral data using a normalized area over reflectance curve (NAOC)
2010
Abstract The Normalized Area Over reflectance Curve (NAOC) is proposed as a new index for remote sensing estimation of the leaf chlorophyll content of heterogeneous areas with different crops, different canopies and different types of bare soil. This index is based on the calculation of the area over the reflectance curve obtained by high spectral resolution reflectance measurements, determined, from the integral of the red–near-infrared interval, divided by the maximum reflectance in that spectral region. For this, use has been made of the experimental data of the SPARC campaigns, where in situ measurements were made of leaf chlorophyll content, LAI and fCOVER of 9 different crops – thus, …
Mapping Carbon Stocks In Central And South America With Smap Vegetation Optical Depth
2019
Mapping carbon stocks in the tropics is essential for climate change mitigation. Passive microwave remote sensing allows estimating carbon from deep canopy layers through the Vegetation Optical Depth (VOD) parameter. Although their spatial resolution is coarser than that of optical vegetation indices or airborne Lidar data, microwaves present a higher penetration capacity at low frequencies (L-band) and avoid cloud masking. This work compares the relationships of airborne carbon maps in Central and South America with both (i) SMAP L-band VOD at 9 km gridding and (ii) MODIS Enhanced Vegetation Index (EVI). Models to estimate carbon stocks are built from these two satellite-derived variables.…
ATLAS beam test results
1996
Many different configurations of electronics and-semiconductor strip detectors were studied in 1995 using the ATLAS tracking detector test area at the H8 beam-line of the CERN SPS. A significant fraction of these investigations are presented elsewhere in this volume and this paper will concentrate on the results with silicon strip detectors read out with electronics preserving the pulse height information. Data has been collected with the ADAM, APV5 and FElix read-out chips on a number of different detectors. The first results are presented for read out with LHC electronics of detectors to the ATLAS-A specification of 112.5 mu m pitch, employing n-strips in n-type silicon, capacitive coupli…
Gas—liquid chromatographic analyses
1984
Abstract The gas chromatography (GC) of n -alkyl acetates (CH 3 COOR), chloroacetates (CH 2 ClCOOR), dichloroacetates (CHCl 2 COOR) and trichloroacetates (CCl 3 COOR), where the alcohol chain length (R) varied between 1 and 8, and certain of their monochlorinated derivatives, 176 compounds altogether, has been studied on SE-30 and OV-351 glass capillary columns under the same operating conditions. The isomeric monochlorinated esters are eluted in direct order from the 1- chloro to the ω-chloro isomer, the separation of the isomers being complete on OV- 351. On SE-30, however, the peaks of the 6- and 7-chlorooctyl esters are partly overlapped. The separation of the mixtures of odd- and e…
Algunas reflexiones acerca de la stjue de 9 de julio de 2020 sobre los pactos novatorios en materia de cláusulas suelo
2021
The Sentence of the Court of Justice of the European Union of July 9, 2020 comes to answer the five questions that, in its preliminary question, the Court of First Instance and Instruction No. 3 of Teruel asks about the validity of the new agreements in the context of the floor clauses, establishing jurisprudential doctrine on this matter about which our Supreme Court had previously ruled in its Judgments of October 16, 2017, in the sense of considering the agreed floor clause null as a consequence of the novation agreement and, subsequently, those of April 11, 2018 and September 13, 2018 in the opposite direction, declaring that the novation agreement was valid. It is a long-awaited and in…
Radiation-induced vascular changes in the intracranial irradiation field in medulloblastoma survivors: An MRI study
2019
While survival times after treatment of medulloblastoma are increasing, little is known about radiochemotherapy (RCT)-induced cerebrovascular changes. High resolution vessel wall imaging (VWI) sequences are an emerging tool for the evaluation of cerebrovascular diseases. We performed VWI in medulloblastoma long-term survivors to screen for late sequelae of RCT.Twenty-two pediatric medulloblastoma survivors (mean age 25.8 years (10-53 years); 16.3 years (mean) post primary RCT (range 1-45 years)) underwent 2D VWI-MRI. Vessel wall thickening, contrast enhancement and luminal narrowing were analyzed. The findings were correlated with the patients' radiation protocols.Vessel wall changes were o…
Correlation of high-field and zero- to ultralow-field NMR properties using 2D spectroscopy
2021
The field of zero- to ultralow-field (ZULF) nuclear magnetic resonance (NMR) is currently experiencing a rapid growth, owing to the progress in optical magnetometry, and also attractive features of ZULF NMR, such as low hardware cost and excellent spectral resolution achieved under ZULF conditions. In this work, an approach is proposed and demonstrated for simultaneous acquisition of ZULF-NMR spectra of individual 13C-containing isotopomers of chemical compounds in a complex mixture. The method makes use of fast field cycling, so that the spin evolution takes place at ZULF conditions, whereas signal detection is performed in a high-field NMR spectrometer. This method has excellent sensitivi…
Nondestructive full-field imaging XANES-PEEM analysis of cosmic grains
2006
For chemical analysis of submicron particles, mass spectrometric methods have the disadvantage of being destructive. Thus, a nondestructive elemental and chemical mapping with a high spatial resolution prior to mass analysis is extremely valuable to precharacterize the sample. Here, first results are presented of combined XANES (x-ray absorption near-edge structure) and PEEM (photoemission electron microscopy) measurements on a cosmic grain fraction from the Murchison meteorite. This nondestructive full-field imaging method is well suited for a quantitative analysis and for a preselection prior to detailed mass spectrometric investigations with isotopic resolution/selectivity. A spectral un…
Red and far-red sun-induced chlorophyll fluorescence as a measure of plant photosynthesis
2015
Remote estimation of Sun-induced chlorophyll fluorescence emitted by terrestrial vegetation can provide an unparalleled opportunity to track spatiotemporal variations of photosynthetic efficiency. Here we provide the first direct experimental evidence that the two peaks of the chlorophyll fluorescence spectrum can be accurately mapped from high-resolution radiance spectra and that the signal is linked to variations in actual photosynthetic efficiency. Red and far red fluorescence measured using a novel airborne imaging spectrometer over a grass carpet treated with an herbicide known to inhibit photosynthesis was significantly higher than the corresponding signal from an equivalent untreated…
Synthesis and Isolation of Enantiomerically Enriched Cyclopenta[b]benzofurans Based on Products from Anodic Oxidation of 2,4-Dimethylphenol
2015
The anodic treatment of 2,4-dimethylphenol offers a powerful and direct method for the construction of a dehydrotetramer with four contiguous stereocentres on a multigram scale. The installation of propellanes on this scaffold using enantiomerically pure carbonyl compounds leads to a mixture of diastereomers. This mixture is easily separable using standard chromatography and gives rise to optically pure cyclopenta[b]benzofurans which are important scaffolds in a variety of natural products. The synthesis is easy to perform and allows a reliable access to chiral compounds with very high enantiomeric excess. It was possible to determine the absolute configuration of these compounds by compari…