Abstract: There is disclosed a method for the protection of metal surfaces against corrosion by the formation of a passivating coating of zinc silicate on the surfaces of the metals exposed to the water. The metal surfaces are preconditioned by contact with water containing a soluble zinc salt in an amount from about 0.5 to about 5 parts zinc per million weight parts of the water while the total alkalinity is maintained above 100 millequivalents by the addition of a water soluble alkaline material, as needed. The pretreatment passivates the metal surfaces with a coating of zinc carbonate, as can be determined by measuring the magnitude of external current flow between electrodes of a test probe maintained in the water.

Abstract: A corrosion inhibited sodium and calcium chloride composition preferably in granular form, which is uniformly coated with a minute to minor quantity of an inhibitor comprising chiefly superphosphate and a minor amount of magnesium oxide. There is also disclosed a method for inhibiting corrosion of sodium and calcium chloride which comprises supplying to the metal surface which is exposed to corrosive attack by sodium and calcium chloride, a minute quantity of an inhibitor comprising chiefly superphosphate and a minor amount of magnesium oxide. The magnesium oxide functions to cement the inhibitor as a tenacious coating on the salt granules, and also to enhance the effectiveness of the phosphate corrosion inhibition.

Abstract: A pulse train divider circuit includes a first flip-flop (1) whose Q output is connected to the D input of a second flip-flop (2) whose Q output is connected to the D input of the first flip-flop (1). A pulse train to be divided is applied via an input (3) directly to the clock input C of the first flip-flop (1) and via a circuit (4) which delays the pulse train applied to the clock input C of the flip-flop (2) to provide a given phase relationship between the pulse trains at the two clock inputs. The circuit divides-by-two, and the resulting divided pulse trains available at the various outputs have phase relationships depending on the phase relationship of the applied pulse trains at the clock inputs.

Abstract: A system including a receiver which receives scrambled signals and subjects them to a descrambling process under the control of control words periodically conveyed to the receiver by a conditional access sub-system. A new control word is required for every 256 television frames constituting a descrambling period, which control word is transmitted during the preceding descrambling period. In order to reduce the time taken to initiate the descrambling process upon selection of a particular service or following an interruption therein, the initial control word then conveyed to the receiver is that for the 256 frame descrambling period following the existing descrambling period. The initial control word is followed by the control word for the existing descrambling period. Subsequent control words are successively conveyed to the receiver during the descrambling intervals preceding those to which such control words are respectively applicable.

Abstract: A receiver having an interface arrangement for connection between a television circuit and a conditional access sub-system conveys data via a bus having a four frame bus cycle period with a bit rate corresponding to the line rate. During a first part of the bus cycle period data is conveyed from the receiver to the sub-system sequentially as follows:i. an address block of 1 byte with the unique address of the sub-system with which the receiver is in communication,ii. a status block of 1 byte providing status information for the following blocks in the first part,iii,iv,v. three data blocks each of 93 bytes and each containing an entitlement message,vi. a keying block of 1 byte conveying keyboard or remote control commands, andvii,viii. a further block of either 1/2 byte (vii) or 21/2 bytes (vii+viii) conveying frame count information.

Abstract: An interface arrangement between a television receiver (1) and a conditional access sub-system (3), in particular for MAC type television signals comprises a bus having a first line (CKFH) conveying clock signals at television line frequency, a second line (DATA) conveying data during prescribed periods in a four television frame period bus cycle and a third line (DIRN) conveying a signal indicating the direction of data travel on the second line. The bus may be connected to a number of sub-systems (3(1), 3(2)) internal to the television receiver or may be connected via a connector unit (7) to external sub-systems (5(1), 5( 2)).

Abstract: In a magnetic disk file having a plurality of disks and a source of organic lubricant mounted within a housing, an air flow stream recirculates within the housing. The vapor pressure of the lubricant source is controlled to provide vapor phase transport of lubricant molecules between the source and the disks' recording surfaces. The lubricant molecules bidirectionally transfer between the air stream and the source, and between the air stream and the surface of the disks, as is needed to maintain a mono-molecular lubricant film, in the range of about 3 to 15 angstroms, on the disks in accordance with the principle of Langmuir kinetics. The disks are rigid disks and their recording surface includes a carbon overcoat. This overcoat has an affinity for the airborne organic lubricant molecules.In a first embodiment, the vapor pressure of the lubricant is controlled by mounting the material at the coolest location within the housing.

Abstract: In a receiver for a C-or D-MAC Packet television signal the bits of a pocket from the first subframe (DATA `A`) are multiplexed with the bits of a correspondingly positioned packet in the second subframe (DATA `B`) and applied to a data line of a packet bus so that the bits from the two packets alternate (DATA).

Abstract: A receiver for recovering sound/data information for a number of services transmitted digitally as a packet multiplex has the data, after demodulation, applied to a first unit (3) where it is resynchronized for application to a sync and data extraction unit (19). In the extraction unit (19) the data packets are processed and applied, at a different clock rate, to a packet bus (25) to which a desired number of packet digital sound recovery devices (26) and packet encryption recovery devices (27) are connected. Instead of each recovery device (26, 27) interrogating all the packets of data those packets carrying a service identification address are processed in the extraction unit (19) and service addresses for user selected services are applied from a microcomputer (23) over an I.sup.2 C bus to the recovery devices (26, 27), control information also being received and interpreted by said extraction unit (19) and applied in similar manner to the recovery devices (26, 27).

Abstract: In television transmitter equipment for a television transmission system having a time multiplexed signal in component form, the vision components are derived from a vision source (1), encoded in a MAC encoder (2) and the encoded vision signals are modulated in a frequency modulator (3) which also receives oscillations from an oscillator (4). The modulated output of the frequency modulator (3) is applied through a multiplexer (5) to a transmitter (6) whose modulated carrier is applied to a dish aerial (7) for transmission to a satellite. The equipment contains a number of sources (8 to 15) of sound/data information which are separated into two groups, an `A` group of sources (8 to 11) and a `B` group of sources (12 to 15). Digital signals from the `A` group sources are applied to an `A` packet multiplexer (17) where the signals are assembled packet-by-packet into a given time area at a bit rate of 10.125 MHz.

Abstract: A wide-band frequency modulated DBS signal of the type having time sequential compressed chrominance and luminance (video) components is received by an aerial (1), frequency converted in a down converter (2) and applied to the input (4) of a conversion unit. The conversion unit has a tuner (5), i.f. stage (9,10) and a frequency demodulator (11) to produce baseband video which is applied after de-emphasis at (12) to a modulator (27) where the video is amplitude modulate onto a vision carrier from an oscillator (28). The modulated carrier is applied through a vestigial sideband filter (29) and an adder (30) to an output (31). Sound/data bursts present in the DBS signal are recovered in a stage (13) and processed in a processor (14) where the sound/data bursts are expanded to occupy approximately a line period at a bit rate which is an integral sub-multiple of the bit rate for the sound/data bursts in the received DBS signal.

Abstract: A process for producing a reactive ion-etched structure with height and width dimensions of the order of 25 microns or less on a ferrite substrate surface is disclosed. A mask of positive water saturated photoresist is formed on the substrate. A metal taken from the group consisting of nickel and a nickel-iron alloy is plated through the mask. The photoresist mask is removed to leave a pattern in the plated metal. The ferrite substrate surface that is exposed by the pattern is reactive ion etched with a power density of >1w/cm.sup.2 and a bias voltage <-100 volts.

Abstract: An apparatus for making cylindrical polyurethane foam blocks, including an upstanding trough with a weir structure at the upstream end of a fall plate in a molding apparatus, means for passing a first web of a separation sheet below the trough and between a gap formed between the weir and the fall plate leading edge, means for forming the first web into a U-shaped configuration as it advances with the foaming material, and second means for feeding opposite webs of sheet material immediately upstream of the conveyor through molding means for forming the cylindrical block.

Abstract: Method for prevention of corrosion of iron and mild steel surfaces in contact with water. The invention is primarily directed to treatment of potable water such as municipal waters and the like which have limits on the concentrations of additives such as phosphates and the like that have been previously employed for corrosion inhibition. It has been found that the addition of a limited amount of an orthophosphate buffer such as phosphoric acid or sodium dihydrogen orthophosphate greatly reduces the concentration of a hexametaphosphate corrosion inhibitor necessary for passivation of metal surfaces and the necessary level of the metaphosphate for maintaining the passivating film.

Abstract: There is disclosed a method for the preparation of an oxidant-containing solid which is useful as an antiseptic agent, bleaching agent, oxidizing agent, etc. The solid, which can be prepared in a varied degree of water solubility, is prepared by reacting, in aqueous solution an alkali metal silicate with an oxidant which can be hydrogen peroxide or an alkali metal hypohalite. When a hypohalite is used as the oxidant, the resultant solid can be prepared in a varied degree of water solubility. Typically, a solution of sodium silicate is admixed with a solution of sodium hypochlorite, resulting in the formation of a voluminous, white precipitate that can be separated by filtration, decanting and the like, to obtain a solid containing the hypochlorite. The water solubility of this solid can be readily controlled by progressive dehydration of the solid, resulting in increasing water insolubility of the solid.