Abstract: A method for shielding the magnetic field generated by an electrical power transmission line and an electrical power transmission line so shielded. The electrical power transmission line has at least one electrical cable and at least one shielding element made of ferromagnetic material arranged in a radially outer position with respect to the at least one cable which shielding element has a base and a cover. The line also has a supporting element coupled to at least the base of the shielding element. In particular, the ferromagnetic material of the shielding element is selected from grain oriented silicon steel, preferably containing a silicon content between about 1% and about 5%, non-grain oriented silicon steel, Permalloyè and Supermalloyè.

Abstract: A process for manufacturing a cable includes the steps of conveying at least one conductor to an extruder apparatus; extruding an insulating coating layer radially external to the at least one conductor; longitudinally folding a metal tape around the extruded insulating coating layer, the metal tape bearing at least one adhesive coating layer in a radially external position; and extruding at least one continuous coating layer of at least one polyamide or a copolymer thereof around and in contact with the folded metal tape. The step of extruding the at least continuous coating layer is carried out at a draw down ratio not higher than 2.5, preferably, 1.2 to 2.0.

Abstract: A method for feeding a flow of gas to a burner for manufacturing an optical fiber preform. The burner has a plurality of coaxial tubes, each two adjacent coaxial tubes defining an annular channel between themselves; an annular gas distribution chamber at one extremity of the annular channels and in fluid communication therewith, the annular distribution chamber being delimited in the radial direction by an inner and an outer surface. The flow of gas is introduced into the distribution chamber so that the direction of its radially outermost portion is tangential to the radially outer surface of the distribution chamber. The method allows obtaining a better gas velocity distribution in the annular channels.

Abstract: An optical fiber link has a plurality of optical fiber spans joined one to the other, the plurality of optical fiber spans including at least one first unidirectionally-spun optical fiber span and at least one second unidirectionally-spun optical fiber span having mutually opposite spinning directions.

Abstract: An optical cable for communication includes at least one micromodule, wherein the micromodule is blocked with respect to the propagation of water. The at least one micromodule includes at least one optical fiber, a retaining element for housing the at least one optical fiber, and a thixotropic filling compound arranged within the retaining element. The filling compound is thixotropic, has a viscosity higher than or equal to 700 Pa·s at zero shear rate and at a first temperature of 20° C., a loss modulus G? lower than or equal to 3000 MPa at 1 Hz and at a second temperature of ?45° C., and is compatible with the retaining element.

Abstract: A cable for use in a predetermined voltage class includes at least one conductor; at least one extruded insulating layer surrounding the conductor, the insulating layer being made from a non-crosslinked insulating material having at least one thermoplastic polymer and at least one dielectric liquid, the insulating layer having a thickness such as to provide a voltage gradient on the outer surface of the cable insulating layer not smaller than 1.0 kV/mm; and a protective element around the extruded insulating layer having a thickness and mechanical properties selected to provide a predetermined impact resistance capability, the protective element having at least one expanded polymeric layer, the thickness being sufficient to prevent detectable insulating layer damage upon impact of at least 25 J energy.

Abstract: A cable for use in a predetermined voltage class, has a conductor; an insulating layer surrounding the conductor, the insulating layer having a thickness selected to provide a predetermined electrical stress when the cable is operated at a nominal voltage in said predetermined voltage class; and a protective element around the conductor having a thickness and mechanical properties selected to provide a predetermined impact resistance capability, the protective element having at least one expanded polymeric layer. The insulating layer thickness and the protective element thickness are selected in combination to minimize the overall cable weight while preventing a detectable insulating layer damage upon impact of 50 J energy. A method for designing a cable is also disclosed.

Abstract: A device including at least one gripping member, rotatably mounted about an axis Z-Z, adapted to hold at least one end of at least one elongated element for chemical vapour deposition for forming a preform. The device includes at least one burner being mobile along a direction substantially parallel to the axis Z-Z and adapted to deposit, on the elongated element, a chemical substance for forming a preform, and at least one suction element arranged on the opposite side of the burner on a portion of a wall of the device on the opposite side of the gripping member from the burner. At least one air suction member, mobile along direction Z, is provided with motion synchronous with respect to the burner. The wall with the air suction member has a pair of respective upper and lower tapes rigidly associated with the burner.

Abstract: A cable comprises at least two cores stranded together, an expanded inner jacket layer, a substantially circular metallic armor partially contacting the inner jacket to form unfilled interstices outside the inner jacket, and a polymeric outer jacket. The expanded inner jacket substantially takes the shape of the periphery of the stranded cores, providing a non-circular cross section for the expanded inner jacket. A method of producing a cable comprises providing at least two cores, expanding a polymeric material, extruding the expanded polymeric material around the cores, and allowing the expanded polymeric material to collapse onto the cores. A substantially circular metallic armor is applied, resulting in a plurality of unfilled voids between the inner jacket and the metallic armor. An outer jacket is extruded on the metallic armor.

Abstract: An optical fiber cable having a polymeric component, in particular a buffer tube, suitable for both terrestrial and undersea uses. The polymeric material forming the component has a copolymer of propylene with a C4-C8 ?-olefin and preferably a nucleating agent disbursed therein. The obtained component shows improved dimensional stability, which guarantees its non-deformability, and high transparency and can be extruded at lower extrusion temperatures.

Abstract: A process for manufacturing a multipolar cable having at least one pair of cores, each core having at least one conductive element and at least one layer of electrical insulation in a position which is radially external to the at least one conductive element. The process includes the steps of: a) assembling said at least one pair of cores so as to form an assembled element having a plurality of interstitial zones between the cores, and b) depositing by co-extrusion an expandable polymeric material in a position which is radially external to the cores so as to fill the interstitial zone and to form a filling layer of substantially circular transverse cross section, and at least one containment layer of polymeric material in a position radially external to the filling layer. The multipolar cable obtained from the process.

Abstract: A method and device for manufacturing a preform for optical fibres through chemical deposition on a substrate for deposition arranged vertically. A chemical deposition chamber includes at least one gripping member rotatably mounted about an axis Z-Z and adapted to hold at least one end of at least one elongated substrate for chemical deposition for the formation of a preform. The chamber includes at least one burner which is mobile along a direction Z substantially parallel to the axis Z-Z and adapted to deposit on the elongated substrate, a chemical substance for the formation of a preform and at least one suction element for collecting exhaust chemical substances. The suction element is arranged on the opposite side of the burner with respect to the axis Z-Z and is mobile along the direction Z and is positioned at a lower height than the burner.

Abstract: A process for manufacturing an electric cable. In particular, the process includes the steps of: a) feeding a conductor at a predetermined feeding speed; b) extruding a thermoplastic insulating layer in a position radially external to the conductor; c) cooling the extruded insulating layer; and d) forming a circumferentially closed metal shield around the extruded insulating layer. The process may be carried out continuously, i.e., the time occurring between the end of the cooling step and the beginning of the shield forming step is inversely proportional to the feeding speed of the conductor.

Abstract: Multi-flame burner wherein each flame is separated with respect to the neighboring flame by at least one separating tube made of a heat resistant material, for example, quartz glass or ceramic material. The burner also has a plurality of co-axial pipes, preferably made of a metallic material. The cross section of the upper end of the separating tube can be modified in order to increase the deposition rate of the burner. Methods for manufacturing optical fibre preforms by vapour deposition using the multi-flame deposition burners.

Abstract: A device for manufacturing a preform of glass material for optical fibres. A chemical deposition chamber, at least one burner mobile along a direction Z and adapted to deposit a chemical substance on at least an elongated element positioned along an axis Z-Z, at least one suction element mobile along the direction Z for collecting exhaust chemical substances, a collector tube associated with the at least one suction element and adapted to discharge the exhaust chemical substances outside the chemical deposition chamber through an exhaust opening formed on a wall of the chamber, and a coupling device between the collector tube and the wall at the exhaust opening, allowing sliding of the collector along the direction Z and along a direction X towards/away from the axis z-z.

Abstract: An apparatus for producing a low-PMD optical fiber having a furnace for melting a lower portion of an optical preform; a traction device for pulling an optical fiber from the lower portion of an optical preform; a spinning device for imparting a substantially constant and unidirectional spin to the optical fiber as it is pulled, which causes the fiber to undergo an elastic torsion; a winding device for winding the optical fiber onto a reel; and a twisting device for imparting to the spun optical fiber a unidirectional twist in a direction opposite the elastic torsion, so as to control the residual twist in the optical fiber. A process for producing the fiber, an optical fiber and a cable are also provided.

Abstract: A method of determining characteristic spin parameters of a spun optical fiber by performing optical time-domain reflectometry measurements on the fiber, so as to obtain a state of polarization spatial function from a backscattered electromagnetic field, the state of polarization spatial function being defined by a plurality of components; and processing the state of polarization spatial function. The process includes calculating a further spatial function related to the spatial first derivative of at least one of the components of the state of polarization spatial function; identifying a spatial periodicity of the further spatial function; and determining the characteristic spin parameters as a function of the spatial periodicity.

Abstract: Optical cable, in particular for submarine connections. A water blocking resin filling composition of reduced hardness is disposed into interstices. Preferably, the resin composition is a polyurethane resin having less than about 35% by weight of a polyol/polyisocyanate mixture and about 60% to about 90% by weight of a mineral oil. The polyurethane resin preferably has less than about 12% by weight of a coupling agent. The cable has an optical core surrounded by a plurality of metallic wires and an outer polymeric sheath. The optical core is of the “tight” type with a plurality of optical fibers embedded into a polymeric matrix disposed around a strength member.

Abstract: An extrusion method and apparatus (11) for producing a cable (1, 101) including at least one core (7) comprising at least one transmissive element (2, 40), and at least one pair of coating layers (8, 9) arranged at a radially outer position with the respect of the core (7) are described. The method of the invention includes the simultaneous steps of depositing by co-extrusion at least one coating layer (8) of polymeric material and one coating layer (9) of expanded polymeric material and of maintaining a residual pressure not greater than the external pressure in a substantially annular interspace (21) defined between the coating layers. With respect to the methods of the prior art, the present invention allows to avoid the formation of bubbles at the interface between said at least one coating layer (8) of polymeric material and the coating layer (9) of expanded polymeric material, attaining an optimal adhesion between said layers (8, 9).

Abstract: An optical fiber cable has a highly reduced diameter. The cable has a central strength member; a number of tubes containing loosely arranged optical fibers, each tube having a thickness, and each optical fiber having a coating; and a protective outer jacket, wherein the filling coefficient of optical fibers in at least one loose tube is ?45°/0. The tubes are made of a material having an elasticity modulus ?700 MPa; and the optical fibers are SM-R fibers having a microbending sensitivity ?4.0 dB·km?1/g·mm?1 at a temperature of about ?30° C. to +60° C. at about 1550 nm.