Abstract: Thermoplastic linear aromatic polyetherdiketones containing repeating units of formula: ##STR1## wherein R is an arylene radical containing from 1 to 3 aromatic rings directly joined among them, or condensed, or joined by one or more of the following difunctional groups:--O--, --CO--; --CO--CO--, --SO.sub.2 --, --C(CH.sub.3).sub.2 --, --C(CF.sub.3).sub.2 --.

Abstract: Mixed oxides of alumina and zirconia having a controlled granulometric distribution, consisting essentially of spherical, submicronic particles, wherein zirconia is distributed uniformly in alumina and may reach 38% by weight, said zirconia being in the stabilized form at room temperature in the tetragonal phase, after having subjected the amorphous hydrated composite oxides to thermal treatments, wherein occurs the transition of zirconia to the tetragonal phase.

Abstract: The biotechnological resolution by means of stereoselective enzymatic thio-transesterification of the racemic mixture of the optical isomers of the compounds of formula (I): ##STR1## wherein: R, R' and R", alike or different form one another, represent a linear alkyl group of from C.sub.1 to C.sub.4, in the presence of an alcohol and an enzyme capable of selectively causing the reaction of thio-transesterification of the (L)-isomer to take place, with the (D)-isomer remaining substantially unchanged, and being then separated by means of per se known techniques.

Abstract: Thermotropic liquid-crystalline aromatic polyesters processable in the molten state, comprising units derived from at least one dicarboxylic aromatic acid and from mono- and di-substituted (1-phenyl-ethyl)-hydroquinones in admixture with hydroquinone, and/or hydroquinones substituted with halogen or alky, aryl or cycloalkyl groups.

Abstract: Liquid-crystalline, thermotropic, aromatic polyesters processable in the molten state, comprising units derived from hydroquinones substituted with aryl, aralkyl and aroyl groups, and from phenoxy-hydroquinone.

Abstract: Modified impact-resistant vinylaromatic copolymers containing from 2 to 10% by weight of an ethylenically unsaturated nutrile and from 0 to 30% by weight of alpha-methyl-styrene and having a gel content higher than 23%, a cracking resistance, in an olive oil/oleic acid mixture under a load of 10 MPa, higher than 100 min., and a melt index below 1.5 g/10 minutes.

Abstract: Perfluoropolyethers having an average molecular weight higher than 390 and respectively having a kinematic viscosity lower than 8.5 cSt (at 20.degree. C.), and such as to distill by not more than 10% at temperatures lower than 140.degree. C., and by at least 90% at temperatures not higher than 260.degree. C., or, in the case in which the perfluoropolyether does not contain CF(CF.sub.3)CF.sub.2 O units, having a viscosity lower than 18 cSt (at 20.degree. C.), and such as to distill by not more than 10% at temperatures lower than 140.degree. C., and by at least 90% at temperatures not higher than 280.degree. C., are used as the only high-temperature and low-temperature working fluid in the Thermal Shock Tests to which the electronic components are submitted, and at the same time are advantageously used in other tests used in the electronic industry, such as the Gross Leak Test and the Burn in Test, allowing the operators in this field to use one single fluid for a whole set of uses.

Abstract: Thermotropic liquid crystalline polyesters which can be processed in the molten state containing moieties derived from a dicarboxylic aromatic acid and 2,5-dihydroxybenzophenone eventually in a mixture with a substituted hydroquinones.

Abstract: A differentiating circuit is disclosed for use in asynchronous networks which associates the transfer of information through the circuit with the occurrence of the acquisition of the information by a utilizing circuit. The circuit can be used as a differential signal producer or, in combination with other circuits, to form AND, OR etc. logical circuits having a differentiated signal output.

Abstract: Thermotropic di-s-triazinic derivatives are taught having the general formula: ##STR1## wherein: m is zero or an integer of from 1 to 5,n is an integer of from 5 to 30, andX is a halogen, such as chlorine, or a CH.sub.3 (CH.sub.2).sub.m O-- group.

Abstract: There is disclosed a process for the biotechnological resolution, by enzymatic esterification of the corresponding racemic mixture of the S(+) and R(-) optical isomers of the oxazolidinonic compounds having formula (I): ##STR1## wherein R represents a, linear or branched, C.sub.1 -C.sub.8 alkyl group, which process is characterized in that, the racemic 3-alkyl-5-hydroxymethyl-oxazolidin-2-one derivative of formula (I) is reacted with an esterifying compound, selected from esters having formula (III): ##STR2## wherein R represents a, linear or branched, C.sub.1 -C.sub.10 alkyl or alkenyl group and R" represents a linear or branched, C.sub.1 -C.sub.4 alkyl, alkenyl group, a haloalkyl (chlorine, bromine) group or a diacyl glycerolic group or from acids having formula (IV):R'"--COOH (IV)wherein R'" represents a, linear or branched, C.sub.1 -C.sub.20 alkyl or alkenyl group or from anhydrides having formula (V): ##STR3## wherein R.sup.IV represents a, linear or branched, C.sub.1 -C.sub.

Abstract: This invention relates to composite manufactured articles formed by a set of uniaxially oriented isotatic polypropylene films, having a resistance to delamination of at least 0.4 kg/cm are prepared by heating under pressure a plurality of isotatic polypropylene films superimposed to each other and separated from each other by a non oriented polypropylene films. The oriented films show an orientation of the crystalline phase such as to produce X-ray scattering angles .DELTA..times. equal to or lower than 10.degree.. The non oriented film show an orientation of the crystalline phase such as to produce X-ray scattering angles higher than 20.degree., at a temperature between a temperature equal to or higher than the melting temperature, measured in non restrain conditions, of the non oriented film and a temperature lower than the melting temperature, measured in restrained conditions, of the oriented films.

Abstract: Thermotropic liquid crystalline aromatic polyesters of 4,4'-dihydroxydiphenyl substituted in 3,3' positions by a halogen or by an alkyl, cycloalkyl or aralkyl radical.

Abstract: Thermotropic liquid-crystalline aromatic polyesters of 4,4'-dihydroxy-diphenyl substituted with a halogen or with an alkyl, cycloalkyl, aryl, aralkyl, keto or ether radical.

Abstract: Octa-substituted derivatives of the macrocyclic tetramers obtained by condensation of resorcinol with an alkyl aldehyde, wherein the sutstituents are alkanoyl, p-alkylbenzoyl, and p-alkoxybenzoyl chains. These substituted tetramers show stable, tridimensional, columnar type mesophases wherein the crystalline lattice is formed with the central macrocyclic rings stacked one on another according to ordered columns, each ring being surrounded with alkyl chains in the melted state.

Abstract: Catalysts for the polymerization of alpha-olefins, which comprise the product of the reaction between:(a) a metallorganic compound of Al;(b) an electron-donor compound reactive towards MgCl.sub.2 but which is not completely complexed with AlEt.sub.3, at the equivalent point of a potentiometric titration under standard conditions;(c) a solid comprising a halogenated Ti compound and an electron-donor belonging to particular classes of compounds and being extractable with AlEt.sub.3 for at least 70% by mols from the solid, the surface area of which after extraction is higher than 20 m.sup.2 /g.The present invention refers to new supported components of catalysts for the polymerization of olefins CH.sub.2 .dbd.CHR, in which R is an alkyl with 1-4 carbon atoms or an aryl, and of mixtures of such olefins with each other and/or with ethylene, and to the catalysts obtained from such components.

Abstract: Thermotropic semiflexible polyesters are taught which are obtained by polycondensation of 4,4'-dihydroxybicyclohexyl with at least one .alpha.,.omega.- alkandioic acid of general formula:HOOC-(CH.sub.2).sub.n -COOH (I)wherein n is an integer comprised between 4 and 12.

Abstract: A process for preparing hydrated alumina consisting essentially of spherical particles having a narrow granulometric distribution (polydispersion index dw/dn.ltoreq.2) starting from aqueous solution of aluminum sulphate, the molar ratio SO.sub.4.sup.= /Al.sup.3+ being greater than 1, by homogeneous precipitation in the presence of cationic polyelectrolytes, which are soluble under the reaction conditions and have a mean molecular weight higher than one million and an ionicity, deriving from the cationic groups present in the polyelectrolyte, of at least 3 milliequivalents/gram.

Abstract: Polymeric blends containing 20-80% by weight of a modified vinyl-aromatic polymer containing from 5 to 15% by weight of a ethylenically unsaturated nitrile, and 80-20% by weight of at least one resin containing aromatic groups selected from aromatic polycarbonates and crystalline aromatic polyesters.

Abstract: Derivatives of 2,2-dimethylcyclopropanecarboxylic acid endowed with insecticidal and acaricidal activity, and having the formula ##STR1## wherein: R is an alkyl, cycloalkyl, alkenyl or alkynyl radical having from 1 to 8 carbon atoms, optionally substituted with halogen atoms, or R is an aryl radical optionally substituted with halogen atoms, alkyl or alkoxyl radicals;Y is O or S;X is H, F, Cl, Br, --CH.sub.3, or --CF.sub.3 ;R.sub.1 represents a group having the formula: ##STR2## wherein: X.sub.1 =H or F; X.sub.2 =H, --CN, or --C.tbd.CH; Q=O or CH.sub.2 ; A=CH or N when X1=H, X2=CN and Q=O.