Abstract: An antenna assembly, comprising: a single substrate having a lower surface and an upper surface; an isotropic source of spherical electromagnetic waves configured for emitting surface waves on the upper surface; a ground plane formed on the lower surface comprising a metallic deposit on the entire lower surface; an antenna element formed on the upper surface comprising a periodic patterns metasurface formed on the substrate by a texture of subwavelength patches, the antenna element comprising: a first-scale metasurface defined by a two-dimensional alternation of metal or metamaterial patches having closely spaced vertices in each contiguous element to form small gaps; a plurality of switches disposed in the gap between the vertexes of the patches, each switch permitting to connect several patches through the vertexes for defining a second-scale metasurface having a pattern thus forming the antenna element; wherein each patch has dimensions which do not depend on the frequency of the waves to be radiated, t

Abstract: The invention consists of an apparatus (1) and a method for receiving satellite positioning signals, wherein said apparatus (1) comprises an antenna array (2) comprising at least two antennae (21a,21b,21c,21d) that can receive satellite positioning signals generated by at least one constellation of artificial satellites (C), and at least two phase shifters (22a,22b,22c,22d) positioned downstream of said antennae (21a-21d), wherein the outputs of said phase shifters (22a-22d) are connected to each other by means of an output collector (23), which can be put in communication with a positioning device (4), and wherein in the output collector constructive interference can be generated between the satellite positioning signals and/or disruptive interference can be generated between the reflections of said satellite positioning signals and/or between signals coming from sources located in positions other than those of the satellites of said constellation of artificial satellites (C).

Abstract: An antenna assembly, comprising: a single substrate having a lower surface and an upper surface; an isotropic source of spherical electromagnetic waves configured for emitting surfaces waves on the upper surface; a ground plane formed on the lower surface comprising a metallic deposit on the entire lower surface; an antenna element formed on the upper surface comprising a periodic patterns metasurface formed on the substrate by a texture of subwavelength patches, the antenna element comprising: a first-scale metasurface defined by a two-dimensional alternation of metal or metamaterial patches having closely spaced vertices in each contiguous element to form small gaps; a plurality of switches disposed in the gap between the vertexes of the patches, each switch permitting to connect several patches through the vertexes for defining a second-scale metasurface having a pattern thus forming the antenna element; wherein each patch has dimensions which do not depend on the frequency of the waves to be radiated,

Abstract: System for the disinfection of agricultural soil includes an electric energy source, at least one radiofrequency or microwave generator connected to the electric energy source and arranged to convert the electric energy into electromagnetic power and a plow-like electromagnetic applicator connected to the radiofrequency or microwave generator via wave-guiding lines, the plow-like electromagnetic applicator being arranged to be inserted into the soil so as to transmit the electromagnetic power to the soil, thus obtaining a disinfection of the soil.

Abstract: System for the disinfection of agricultural soil includes an electric energy source, at least one radiofrequency or microwave generator connected to the electric energy source and arranged to convert the electric energy into electromagnetic power and a plow-like electromagnetic applicator connected to the radiofrequency or microwave generator via wave-guiding lines, the plow-like electromagnetic applicator being arranged to be inserted into the soil so as to transmit the electromagnetic power to the soil, thus obtaining a disinfection of the soil.

Abstract: Method for optically resolving an enantiomeric mixture of ethodolic acid to produce the S (+) enantiomer is provided wherein the enantiomeric mixture is salified with at least 0.5 moles per mole of a mixture of alpha-(+)-phenethylamine enantiomers in an organic solvent. The resulting precipitate containing the salt of optically active phenethylamine and the S-(+)-enantiomer of the ethodolic acid is separated followed by isolation of the optically enantiomer. Salification of the acid with organic and inorganic bases, selected from basis amino acids, morpholine, aminopyridine and benzylalkyltrimethylammonium derivatives provides new therapeutically effective derivatives.

Abstract: Process for the preparation of the optically active [6(S)(-)]N.sup.5 alkaline earth metal salts of methyltetrahydrofolic acid and formyltetrahydrofolic acid wherein an aqueous solution of folic acid is hydrogenated with a high stoichiometric excess of sodium borohydride followed by treating the reaction product with formic aldehyde and optionally further with sodium borohydride when the methyl derivative is desired. Reaction with a salt of the alkaline earth metal precipitates the desired optically active alkaline earth metal salt.

Abstract: The pyrrole derivatives having the general formula: ##STR1## wherein X and X' represent H, alkyl, alkoxy, halogen, nitro, amino, and R is H, alkyl, aryl, arylalkyl, cycloalkylmethyl, are active against pathogenic microorganisms, and particularly against mycetes and Gram-positive and Gram-negative bacteria.

Abstract: Commercial carrageenin is purified to render it suitable for pharmaceutical, dietetic and cosmetic use by treatment with hydrogen peroxide in the presence of a hydrated inert organic solvent.