Search results for ""Author Giovanni Sartori""

Encuadernación: Rústica.Nos encontramos en plena revolución multimedia. El homo sapiens, producto de la cultura escrita, se está transformando en un homo videns para el cual la palabra ha sido destronada por la imagen. Y en todo ello la televisión cumple un papel determinante. La primacía de lo visible sobre lo inteligible lleva a un ver sin entender que ha acabado con el pensamiento abstracto, con las ideas claras y distintas.Ésta es la premisa fundamental a partir de la cual el gran pensador italiano Giovanni Sartori examina en esta obra ?ya clásica y, sin embargo, hoy más actual que nunca? la vídeo-política y el poder político de la televisión; la conversión del vídeo-niño en un adulto sordo de por vida a los estímulos de la lectura y del saber transmitidos por la cultura escrita; la formación de la opinión pública, y la cantidad de saber que pasa ?y no pasa? a través de los canales de comunicación de masas.Ante el avance imparable de la edad multimedia aparecerá una nueva

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Used in the production of a wide number of fine chemicals and pharmaceuticals, the Friedel-Crafts acylation reaction represents a synthetic process of great interest to organic chemists of academia and industry. Nearly 40 years since the last major treatise on the topic and reflecting the growing emphasis on green technology, Advances in Friedel-Crafts Acylation Reactions: Catalytic and Green Processes focuses on how to make this reaction more economically and environmentally friendly by using green acylating conditions, thus minimizing the formation of waste and decreasing production costs.Divided into four parts, the book explores stoichiometric acylations, catalytic homogeneous acylations, catalytic heterogeneous acylations, and phenol acylations. It is structured according to the role played by the catalyst in the activation of reagents as well as in the different modes of regioselectivity encountered in the acylation of arenes, aromatic ethers, and phenols. Incorporating examples of all acid-catalyzed Friedel-Crafts acylation reactions, the text considers classic Lewis and Brönsted acid types along with more innovative and advanced multicomponent superacid catalysts. These range from rare earth triflates or triflimides and their combination with ionic liquids to metal-promoted zeolites and zeotypes, clays, polymetal oxides, sulfated zirconia, heteropoly acids, and Nafion. The book emphasizes the major industrial applications, providing a critical assessment of the differences, advantages, and disadvantages of homogeneous and heterogeneous catalysis.Helping readers to better understand the mechanism of the Friedel-Crafts acylation, the examples in the book substantiate the development of more effective catalysts and more selective processes achieved during the last few decades, enabling industry to embark on a safer and more efficient synthesis of aromatic ketones for the manufacture of a wide array of products.

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