797 resultados para Easter Sunday


Relevância:

10.00% 10.00%

Publicador:

Resumo:

El VI Congreso del Partido Comunista de Cuba introdujo una nueva agenda económica que el Gobierno llama la actualización del modelo socialista. Muchos piensan que en esencia se trata de una serie de reformas y reducen su importancia a su dimensión económica. Esta monografía busca explicar la actualización aplicando el análisis de sistemas-mundo de Immanuel Wallerstein, aportando una interpretación no convencional del fenómeno. Se puntualizará en las variables de poder y en los actores políticos que han determinado la nueva política económica: el Partido Comunista de Cuba (PCC) y las Fuerzas Armadas Revolucionarias (FAR). Ambos conforman lo que Wallerstein denomina un movimiento antisitémico. El argumento principal es que el movimiento ha puesto en marcha las reformas buscando fortalecer el Estado y así garantizar su supervivencia al consolidar su posición como el competidor único del poder estatal. Como se verá, estas metas han llevado al movimiento a sacrificar parte de su naturaleza antisistémica.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The study of the atmospheric chemical composition is crucial to understand the climate changes that we are experiencing in the last decades and to monitor the air quality over industrialized areas. The Multi-AXis Differential Optical Absorption Spectroscopy (MAX-DOAS) ground-based instruments are particularly suitable to derive the concentration of some trace gases that absorb the Visible (VIS) and Ultra-Violet (UV) solar radiation. The zenith-sky spectra acquired by the Gas Analyzer Spectrometer Correlating Optical Differences / New Generation 4 (GASCOD/NG4) instrument are exploited to retrieve the NO2 and O3 total Vertical Column Densities (VCDs) over Lecce. The results show that the NO2 total VCDs are significantly affected by the tropospheric content, consequence of the anthropogenic activity. Indeed, they present systematically lower values during Sunday, when less traffic is generally present around the measurement site, and during windy days, especially when the wind direction measured at 2 m height is not from the city of Lecce. Another MAX-DOAS instrument (SkySpec-2D) is exploited to create the first Italian MAX-DOAS site compliant to the Fiducial Reference Measurements for DOAS (FRM4DOAS) standards, in San Pietro Capofiume (SPC), located in the middle of the Po Valley. After the assessment of the SkySpec-2D’s performances through two measurement campaigns taken place in Bologna and in Rome, SkySpec-2D is installed in SPC on the 1st October 2021. Its MAX-DOAS spectra are used to retrieve the NO2 and O3 total VCDs, and aerosol extinction and NO2 tropospheric vertical profiles over the Po Valley exploiting the Bremen Optimal estimation REtrieval for Aerosol and trace gaseS (BOREAS) algorithm. Promising results are found, with high correlations against both in-situ and satellite data. In the future, these data will play an important role for air quality studies over the Po Valley and for satellite validation purposes.