Abstract: The present invention is an improved electric insulation composition of a polymer and an additive that reduces water treeing due to electrical aging in water. The polymer additive is a hydrophobic/hydrophilic material with good compatibility with the polymer. The present invention is also a method of preventing electrical breakdown due to the formation of water trees by forming electrical cables with the insulation containing the disclosed anti-treeing additives.

Abstract: A tubular elastic covering (730) for electric components (700), having on the whole predetermined values of mechanical and electric/environmental requirements, in which the mechanical requirements include expandibility and elastic recovery in a radial direction, and electric/environmental requirements comprise resistance to tracking and resistance to solar radiation, characterized in that said covering includes an inner insulating layer (680) and an outer insulating layer (660) coaxial with each other, in superposed relationship and bonded together, made of blends of cross-linked polymeric material, in which the cross-linked blend forming the inner layer has predetermined values of said mechanical requirements and the cross-linked blend forming the outer layer has predetermined values of said electric/environmental requirements.

Abstract: The present invention is an improved electric insulation composition of a polymer and an additive that reduces water treeing due to electrical aging in water. The polymer additive is a hydrophobic/hydrophilic material with good compatibility with the polymer. The present invention is also a method of preventing electrical breakdown due to the formation of water trees by forming electrical cables with the insulation containing the disclosed anti-treeing additive.

Abstract: A superconducting cable (1) for high power with at least one phase comprises a superconducting core (2) wherein a plurality of elements (3) are housed, which are structurally independent and magnetically uncoupled, each of which includes—for each phase—a couple of phase and neutral coaxial conductors, each formed by at least a layer of superconducting material, electrically insulated from one another by interposition of a dielectric material (8). Thanks to the distribution of the superconducting material into several coaxial conductive elements (3), the cable (1) allows to transmit high current amounts in conditions of superconductivity, while using a high-temperature superconducting material sensitive to the magnetic field.

Abstract: A tubular elastic covering (730) for electric components (700), having on the whole predetermined values of mechanical and electric/environmental requirements, in which the mechanical requirements comprise expandibility and elastic recovery in a radial direction, and electric/environmental requirements comprise resistance to tracking and resistance to solar radiation, characterized in that said covering comprises an inner insulating layer (680) and an outer insulating layer (660) coaxial with each other, in superposed relationship and bonded together, made of blends of cross-linked polymeric material, in which the cross-linked blend forming the inner layer has predetermined values of said mechanical requirements and the cross-linked blend forming the outer layer has predetermined values of said electric/environmental requirements.

Abstract: A polymeric composition for coating electric cables for power transmission at medium/high voltage, having an improved resistance against the formation of the so-called water trees, comprises a polymeric polyolefin base including, in parts by weight to the total weight thereof, from 0.5 to 15 parts of ester groups and from 0.01 to 5 parts of epoxy groups. Electric cables according to the invention comprise at least one electrically conducting core (2) and an insulation coating (5) comprising the aforementioned polymeric composition.

Abstract: A tubular elastic covering for electric components is provided to obtain predetermined values of mechanical and electric/environmental requirements. The mechanical requirements include expandibility and elastic recovery in a radial direction. The electric/environmental requirements include resistance to tracking and resistance to solar radiation. The covering includes an inner insulating layer and an outer insulating layer coaxial with each other, in superposed relationship and bonded together. The covering is made of blends of cross-linked polymeric material, in which the cross-linked blend forming the inner layer has predetermined values of the mechanical requirements and the cross-linked blend forming the outer layer has predetermined values of the electric/environmental requirements. This invention also describes a method of making this covering, a termination for electric cables utilizing this covering, and a method of mounting the termination to an electric cable.

Abstract: A process for producing a multifilamentary conductive tape of the type including a plurality of layers of a high-temperature superconducting material, incorporated in a mutually spaced relationship within a metal matrix, includes the steps of: a) submitting to plastic deformation individual metal tubes including a precursor of a superconducting material, so as to obtain a plurality of elementary tapes structurally independent from one another; b) coupling the tapes so obtained by means of a heat treatment at a temperature and for a time sufficient to establish a stable mutual connection between said tapes. The multifilamentary tape so obtained or possibly the independent tapes, are then subjected to at least one sintering step, which may be followed by one or more cycles of plastic deformation and sintering. Advantageously, the process of the invention allows to increase the fill factor of the tape, with a corresponding increase in the critical current in superconductivity conditions.

Abstract: A polymeric composition for coating electric cables for power transmission at medium/high voltage, having an improved resistance against the formation of the so-called water trees, comprises a polymeric polyolefin base including, in parts by weight to the total weight thereof, from 0.5 to 15 parts of ester groups and from 0.01 to 5 parts of epoxy groups. Electric cables according to the invention comprise at least one electrically conducting core (2) and an insulation coating (5) comprising the aforementioned polymeric composition.

Abstract: In a terminal for a high-voltage electric cable the electric cable is terminated at a predetermined height from its entry into the terminal and the electric connection between the cable conductor the overhead line is obtained by a rigid conductor element. The rigid conductor element, preferably a copper pipe, is provided with an elastomeric ribbed coating and is supported by an insulating base preferably made of an epoxy resin. An assembly constructed from an epoxy resin base and a rigid conductor element brings the electric field at the surface to a value consistent with the dielectric strength of the air and is long enough to form an insulation path suited for the installation environment.

Abstract: A superconducting cable for high power with at least one phase includes a superconducting core wherein a plurality of elements are housed, which are structurally independent and magnetically uncoupled, each of which includes—for each phase—a couple of phase and neutral coaxial conductors, each formed by at least a layer of superconducting material, electrically insulated from one another by interposition of a dielectric material. As a result of the distribution of the superconducting material into several coaxial conductive elements, the cable allows to transmit high current amounts in conditions of superconductivity, while using a high-temperature superconducting material sensitive to the magnetic field. The conductive elements are connected at the ends to yield a mean exploitation efficiency of 100%.

Abstract: A digital optical telecommunication method including the steps of: generating a digital modulated optical signal in an optical transmitting station, which signal corresponds to a first electric input signal carrying a piece of information; feeding the modulated optical signal to an optical-fibre line; receiving the modulated optical signal transmitted from the optical-fibre line at an optical receiving station, converting it to an electric form and thereat generating a second digital electric signal; wherein the modulated optical signal is coded in a sequence of elementary information units at a first frequency and wherein the step of generating a second digital electric signal comprises detecting in said converted signal, an electric signal having a second frequency higher than the first frequency and recognizing in said detected signal, the phase of an electric signal at the first frequency by comparing a received sequence of elementary information units with at least one reference sequence and verifying th

Abstract: The process of the invention to make miniaturized multipolar cables includes the steps of combining together a plurality of individually insulated conductors, inserting a filling in a pasty state and containing mineral fillers into the gaps existing between the conductors, partly hardening the filling and disposing the other cable components, in particular the sheath, around the conductors-filling assembly, and letting the filling become completely hard within the produced cable.

Abstract: Method for the preparation of a polymeric mixture for cable insulators and coatings and sheaths for optic fiber cables; polymeric mixture thus produced and the cables containing it.The method is characterized in that one completely mixes, up to the obtainment of a homogeneous composition, (i) from 50 to 80 parts (w/w) of a first thermoplastic polymer which is amorphous, highly resistant to flames and combustion, and consists of an aromatic polyester of isophthalic and terephthalic acid with bisphenol A, and (ii) from 20 to 50 parts (w/w) of at least a second thermoplastic polymer consisting of an elastomeric polyether-ester block copolymer, having a Shore D hardness greater than 50 and a Vicat softening point greater than 170.degree. C., for a mixing time less than 10 minutes.

Abstract: An apparatus for protecting optical fiber devices having at least one optical fiber length and control means associated therewith, includes a casing having at least one housing passing through the casing, in which casing the optical fiber length is inserted in such a manner that it is located inside the casing itself, in the presence of sealing means interposed between the housing and the casing, so that the housing is delimited in a substantially impervious manner with respect to the casing.

Abstract: A digital optical telecommunication method including the steps of: generating a digital modulated optical signal in an optical transmitting station, which signal corresponds to a first electric input signal carrying a piece of information; feeding the modulated optical signal to an optical-fiber line; receiving the modulated optical signal transmitted from the optical-fiber line at an optical receiving station, converting it to an electric form and thereat generating a second digital electric signal; wherein the modulated optical signal is coded in a sequence of elementary information units at a first frequency and wherein the step of generating a second digital electric signal comprises detecting in said converted signal, an electric signal having a second frequency higher than the first frequency and recognizing in said detected signal, the phase of an electric signal at the first frequency by comparing a received sequence of elementary information units with at least one reference sequence and verifying th

Abstract: A bidirectional optical amplifier, comprising a unidirectional optical amplifying unit having one amplification wavelength band; two input/output ports for at least two optical signals having opposite propagation directions, the signals having a first and a second wavelength respectively, which are distinct from each other and included in the amplification wavelength band; two first and two second wavelength-selective optical couplers, respectively having a first wavelength pass-band including said first wavelength and a second wavelength pass-band including said second wavelength, the first and second wavelength pass-bands being non-overlapping, wherein the amplifying unit is connected between two opposite nodes of an optical bridge circuit, and wherein at the nodes of said bridge circuit the first and second selective optical couplers are present and are disposed symmetrically with respect to the amplifying unit and to the input/output ports of the optical signals.

Abstract: Method for manufacturing an insulating body with a predetermined profile for an electrical device. This method comprises the steps of forming a covering body of cross-linkable polymer material on a supporting element, where said body has a first external profile that comprises the envelope of the predetermined profile; to vulcanize the body; and to create the predetermined profile on the external surface of said body by removing portions of said material. The covering body obtained in monolithic vulcanized polymer material comprises a central element and a plurality of frusto-conical sheds formed on it where the internal conical surface of at least one shed forms an angle of less than 80.degree. with the central element and where the external conical surface of at least one shed forms an angle greater than 110.degree. with said central body.

Abstract: A bidirectional optical amplifier, comprising a unidirectional optical amplifying unit having one amplification wavelength band; two input/output ports for at least two optical signals having opposite propagation directions, said signals having a first and a second wavelength respectively, which are distinct from each other and included in said amplification wavelength band; two first and two second wavelength-selective optical couplers, having a first wavelength pass-band including said first wavelength and a second wavelength pass-band including said second wavelength respectively, said first and second wavelength pass-bands being devoid of relative overlappings, wherein said amplifying unit is connected between two opposite nodes of an optical bridge circuit, and wherein at the nodes of said bridge circuit said first and second selective optical couplers are present, in which said first and second selective couplers are disposed symmetrically to said amplifying unit and to said input/output ports of said o

Abstract: The process calls for extrusion of a multilayer tubular structure with semiconducting innermost layer. In production of the sleeve the inner layer is partially removed leaving only a central portion forming an electrode. In addition the intermediate layer is made with a compound having pre-determined relative dielectric constant and dielectric rigidity.