33 research outputs found
(2RS,4′RS)-3′-(3-Chloro-4-methoxyphenyl)-4′-phenyl-4′H-spiro[indene-2,5′-isoxazol]-1(3H)-one ethanol monosolvate
The title compound, C23H17ClN2O3·C2H6O, is the stoichiometric 1:1 ethanol solvate of a racemic reaction product, which forms a conglomerate. The refined Flack parameter of 0.36 (3) indicates racemic twinning. In the structure, molecules are linked into zigzag chains by a series of intermolecular N—H⋯O and O—H⋯O hydrogen bonds
Ethyl 2-amino-4-phenyl-4H-1-benzothieno[3,2-b]pyran-3-carboxylate
The title heterocyclic compound, C20H17NO3S, was synthesized by condensation of ethyl cyanoacetate with (Z)-2-benzylidenebenzo[b]thiophen-3(2H)-one in the presence of a basic catalyst in ethanol. The phenyl and ester groups make dihedral angles of 77.67 (6) and 8.52 (6)°, respectively, with the benzothienopyran ring system [maximum r.m.s. deviation = 0.1177 (13) Å]. In the crystal, centrosymmetric dimers are formed through pairs of N—H⋯O hydrogen bonds between the amine and ester groups. Intermolecular C—H⋯N hydrogen bonds and C—H⋯π interactions involving the thiophene ring are also observed
3′-(4-Methoxyphenyl)-4′-phenyl-3H,4′H-spiro[1-benzothiophene-2,5′-isoxazol]-3-one
In the title compound, C23H17NO3S, the thiophene and isoxazole rings each have an envelope conformation with the spiro C atom linking them forming the flap of the envelope in each case. The dihedral angle between the mean planes of the benzothiophene ring and isoxazole rings is 81.35 (7)°. In the crystal, an intermolecular C—H⋯O hydrogen bond links the molecules into a chain running parallel to the a axis
Cartografía de alta resolución de la cubierta del suelo y clasificación de los cultivos en la cuenca del Loukkos (norte de Marruecos): Un enfoque que utiliza las series temporales de SAR Sentinel-1
[EN] Remote sensing has become more and more a reliable tool for mapping land cover and monitoring cropland. Much of the work done in this field uses optical remote sensing data. In Morocco, active remote sensing data remain under-exploited despite their importance in monitoring spatial and temporal dynamics of land cover and crops even during cloudy weather. This study aims to explore the potential of C-band Sentinel-1 data in the production of a high-resolution land cover mapping and crop classification within the irrigated Loukkos watershed agricultural landscape in northern Morocco. The work was achieved by using 33 dual-polarized images in vertical-vertical (VV) and vertical-horizontal (VH) polarizations. The images were acquired in ascending orbits between April 16 and October 25, 2020, with the purpose to track the backscattering behavior of the main crops and other land cover classes in the study area. The results showed that the backscatter increased with the phenological development of the monitored crops (rice, watermelon, peanuts, and winter crops), strongly for the VH and VV bands, and slightly for the VH/VV ratio. The other classes (water, built-up, forest, fruit trees, permanent vegetation, greenhouses, and bare lands) did not show significant variation during this period. Based on the backscattering analysis and the field data, a supervised classification was carried out, using the Random Forest Classifier (RF) algorithm. Results showed that radiometric characteristics and 6 days time resolution covered by Sentinel-1 constellation gave a high classification accuracy by dual-polarization with Radar Ratio (VH/VV) or Radar Vegetation Index and textural features (between 74.07% and 75.19%). Accordingly, this study proves that the Sentinel-1 data provide useful information and a high potential for multi-temporal analyses of crop monitoring, and reliable land cover mapping which could be a practical source of information for various purposes in order to undertake food security issues.[ES] La teledetección se ha convertido en una herramienta cada vez más fiable para cartografiar la cubierta vegetal y controlar las tierras de cultivo. Gran parte de los trabajos realizados en este campo utilizan datos ópticos de teledetección. Además, en Marruecos, los datos de teledetección activa siguen estando infrautilizados, a pesar de su importancia para el seguimiento de la dinámica espacial y temporal de la cubierta vegetal y de los cultivos, incluso con tiempo nublado. Este estudio tiene como objetivo explorar el potencial de los datos de la banda C de Sentinel-1 en la producción de una cartografía de alta resolución de la cubierta del suelo y la clasificación de los cultivos dentro del paisaje agrícola de la cuenca del Loukkos de regadío en el norte de Marruecos. Este trabajo se ha realizado utilizando 33 imágenes de doble polarización vertical-vertical (VV) y vertical-horizontal (VH). Las imágenes fueron adquiridas en órbitas ascendentes entre el 16 de abril y el 25 de octubre de 2020, con el propósito de rastrear el comportamiento de retrodispersión de los principales cultivos y otras clases de cobertura del suelo en el área de estudio. Los gráficos obtenidos muestran que la retrodispersión aumenta con el desarrollo fenológico de los tres cultivos monitorizados (arroz, sandía, cacahuetes, cultivos de invierno), fuertemente para las bandas VH y VV, y ligeramente para el ratio VH/VV. Las otras clases (agua, edificado, bosque, árboles frutales, vegetación permanente, invernaderos y tierras desnudas) no muestran una variación significativa durante este periodo. A partir del análisis de retrodispersión y de los datos de campo, se llevó a cabo una clasificación supervisada, utilizando el algoritmo Random Forest Classifier (RF). Los resultados muestran que las características radiométricas y la resolución temporal para los 6 días cubiertos por la constelación Sentinel-1 dan una alta precisión de clasificación por polarización dual con Ratio de Radar (VH/VV) o Índice de Vegetación de Radar y características de la textura (entre 74,07% y 75,17%). En consecuencia, este estudio demuestra que los datos de Sentinel-1 proporcionan información útil y un alto potencial para los análisis multitemporales de seguimiento de los cultivos, así como una cartografía fiable de la cubierta terrestre que debería ser una fuente de información práctica para para varios propósitos a fin de acometer cuestiones de seguridad alimentaria.Nizar, EM.; Wahbi, M.; Ait Kazzi, M.; Yazidi Alaoui, O.; Boulaassal, H.; Maatouk, M.; Zaghloul, MN.... (2022). High Resolution Land Cover Mapping and Crop Classification in the Loukkos Watershed (Northern Morocco): An Approach Using SAR Sentinel-1 Time Series. Revista de Teledetección. (60):47-69. https://doi.org/10.4995/raet.2022.17426OJS47696
Crystal structure of ethyl 2-amino-4-(4-methoxyphenyl)-4H-1-benzothieno[3,2-b]pyran-3-carboxylate
The molecule of the title compound, C21H19NO4S, features a fused ring system whereby a five-membered ring is flanked by two six-membered rings. This is linked to an ethyl 3-carboxylate group and to a methoxybenzene group. The fused-ring system is quasi-planar, with the greatest deviation from the mean plane being 0.131 (1) Å for the methine C atom. The plane through the methoxybenzene ring is nearly perpendicular to that through the fused-ring system, as indicated by the dihedral angle of 85.72 (6)°. An intramolecular N—H...O hydrogen bond is noted. In the crystal, molecules are linked by N—H...O hydrogen bonds, forming layers that stack along the a axis
Ethyl 2-amino-4-(3-nitrophenyl)-4H-1-benzothieno[3,2-b]pyran-3-carboxylate
The molecule of the title compound, C20H16N2O5S, is built up by one fused five-membered and two fused six-membered rings linked to ethoxycarbonyl and 3-nitrophenyl groups. The benzothienopyran ring system is nearly planar (r.m.s deviation = 0.0392 Å) and forms a dihedral angle of 86.90 (6)° with the aromatic ring of the nitrobenzene group. In the crystal, molecules are linked by N—H...O hydrogen bonds and by π–π interactions between the phenyl ring and the six-membered heterocyle [intercentroid distance = 3.5819 (8) Å], forming a three-dimensional network
3′-(4-Chlorophenyl)-4′-phenyl-3H,4′H-spiro[benzo[b]thiophene-2,5′-isoxazol]-3-one
The molecule of the title compound, C22H14ClNO2S, is built up from an isoxazole ring linked to a benzothiophene ring system with additional phenyl and 4-chlorophenyl substituents. The benzothiophene system is virtually planar with the largest deviation from the mean plane being 0.041 (2) Å, while the isoxazole ring adopts an envelope conformation. The plane of the benzothiophene ring system is almost perpendicular to those of the phenyl and the 4-chlorophenyl rings, with dihedral angles of 64.76 (10) and 82.81 (10)°, respectively, between them. The phenyl ring is inclined by 85.76 (12)° to the plane of the 4-chlorophenyl ring, which in turn lies close to the plane of the isoxazole ring. In the crystal, molecules are linked by weak C—H...O hydrogen bonds and offset π–π interactions between the aromatic rings of adjacent benzothiophene ring systems. These combine to form a three-dimensional network structure
Analysis of aperture-coupled circular microstrip antenna
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Ecoulements cellulaires de Stokes dans un canal plan obstrué par une file de cylindres
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