22 research outputs found
Wavelet based multifractal analysis of rough surfaces: Application to cloud models and satellite data
no abstrac
Facile Synthesis of Hydrazine Derivatives of 5H-Pyrrolo[3,4-b]pyrazine and 1H-Pyrrolo[3,4-b]quinoxaline
International audienceA convenient and efficient route for the chemoselective synthesis of carbohydrazide, arenesulfonylhydrazide, and thiosemicarbazone derivatives of 5H-pyrrolo[3,4-b]pyrazine and 1H-pyrrolo[3,4-b]quinoxaline from the corresponding dinitriles and substituted hydrazines was elaborated. The synthesis of starting pyrazine-2,3-dicarbonitrile was sufficiently improved by using concentrated HCl as a catalyst
N-(alkyl)-2-amino-1,4-pyrazine derivatives: Synthesis and antioxidative properties of 3-and 3,5-p-hydroxyphenyl-substituted compounds
2-Amino-5-(p-hydroxyphenyl)-1,4-pyrazine and 2-amino-3,5-bis(p-hydroxyphenyl)- 1,4-pyrazine are endowed with excellent antioxidative properties. For a possible development in medicinal chemistry, the lipophilicity of these lead compounds has to be increased. Therefore various methods of N-alkylation were systematically explored. The best results were obtained by quenching aminopyrazinyl anion with alkyl iodides, and by coupling aldehydes (reductive amination) in the presence of phenylsilane and tin catalyst.
Aminopyrazines equipped with linear alkyl side-chains of at least six carbons showed improved radical-scavenging properties in lipidic media
Instability of a lamellar phase under shear flow: Formation of multilamellar vesicles
no abstrac
Estimation of Mechanical Strength of Unilamellar and Multilamellar AOT/Water Vesicles and Their Rupture Using Micropipet Aspiration
Novel Platinum-Catalyzed Tandem Reaction: An Efficient Approach to Construct Naphtho[1,2- b
Utopian and Developmental Mediterranean Spaces: The Example of the Inland Sea of Martins, Lavigne, Roudaire et al. (1869–1892)
Following the example of the tremendous success of the digging of the Suez Canal during its time, scientific and technical progress led us to believe, for more than a century and a half, in a Nature that could be modelled by Man. The nineteenth century saw the triumph of modern thought (Rabinow 1995) and the figure of the engineer, as well as the proliferation of major projects in the field of land planning, projects nowadays called “utopian”. This resea=rch will attempt to present an example to our emblematic sense of this era: the project of Captain Roudaire on the creation of an Inland Sea (1874–1884) in the southern Algerian and Tunisian borders. Our aim will be to complete the brilliant analytical work done by Olivier Soubeyran and Ahmed Benckeik (1993) by making a new point about the origins of the project and its fertile descent. Thus, we will endeavour to show that the utopian projects do not die and reappear very regularly, according to the current events and the international preoccupations – and it is the case of the Inner Sea – proof that they have not been forgotten and they “haunt” the long-term world of global planning