Abstract: A system for detecting a fault occurred within a substation and judging a location of the fault including optical current sensors each having a Faraday element arranged on a top of an insulator post of a bus disconnecting switch, a magnetic core arranged to surround a terminal plate of the disconnecting switch to generate a magnetic field corresponding to a current passing through the terminal plate, a laser diode for emitting a laser light beam, an optical fiber for guiding the laser beam to the Faraday element, a photodiode, and an optical fiber for guiding the laser beam transmitted through the Faraday element to the photodiode. The photodiode supplies a signal representing the current passing through the terminal plate to a fault location judging circuit in which the fault location within the substation is judged from the signals from the photodiodes.

Abstract: In a system for transmitting an electrical power supply by means of an over-head power transmission line supported by power transmission towers, a fault such as a short-circuit fault and a ground fault is detected by providing optical current sensors having opto-magnetic elements and opto-electric field elements on respective conductors of the transmission line to detect a fault current and fault voltage on the basis of the Faraday's effect and Pockel's effect. Light beams passing through the elements are modulated by the magnetic fields induced by the currents passing through the conductors and the voltages on the conductors, and thus include information about the current and voltage. There is further provided a circuit for calculating a distance to a fault point in accordance with the detected current, voltage and a phase difference therebetween and a known impedance of the power transmission line.

Abstract: A helmet with two-way radio communication faculty including a cap-like outer shell made of hard and electrically insulating plastic material, a cap-like shock absorbing member arranged within the outer shell, an ear-pad member secured to one side edge of the outer shell, a transmitter unit arranged in a top recess formed in an outer surface of the shock absorbing member at its top portion, a receiver unit arranged on an inner surface of the ear-pad member, a battery unit arranged in a side recess formed in the outer surface of the shock absorbing member at its side which is opposite to a side on which the ear-pad member is secured to the outer shell, a transmitting dipole antenna made of a metal foil secured on an inner surface of the outer shell at its one side with the aid of an electrically insulating adhesive tape, and a receiving dipole antenna made of a metal foil secured on the inner surface of the outer shell at its other side with the aid of an electrically insulating adhesive tape.

Abstract: Optical fiber-containing insulators each comprises an insulator body having a through hole provided in its central portion and extending along an axial direction thereof, an optical fiber core wire passing through the through hole, an insulating material filled between an inner peripheral surface of the through hole and the optical fiber core wire, and arrangements for preventing the filled insulating material from axially protruding out of the insulator body even at high temperature or spacers for holding the optical fiber core wire at the central portion of the through hole of the insulator body.

Abstract: A process for producing a reduced keratinous substance having a high adsorptive power for cationic substances, which comprises reducing a substance containing keratin as a main ingredient under alkaline conditions to cleave the disulfide linkages of the keratin, dissolving the reduced keratin in an aqueous medium containing urea or thiourea in a concentration of less than 5 moles/liter, and then acidifying the resulting solution to precipitate the dissolved reduced keratin under such conditions that the thiol side-chains present in the reduced keratin do not substantially undergo oxidation. The reduced keratinous substance is especially useful as a heavy metal ion capturing agent.