Abstract: An asymmetric multi-mode fibre optic coupler is assembled from two or more multi-mode optical fibres of different core and cladding diameters but substantially equal cladding refractive indices. The fibres are selected so as to have substantially equal effective refractive indices for their respective highest-order cladding modes, at least in the fabricated coupler.

Abstract: Apparatus for fabricating a fused biconical taper fibre optic coupler includes a hollow furnace (12) having a longitudinal slot (50). Clamp units (14, 16) are provided to hold at least two suitably prepared optical fibres (8, 9) in intimate side-by-side contact. The clamp units are moveable by motors (18, 20) to relatively laterally move the fibres into and out of the furnace (12) through the slot (50). A power supply (60) heats the furnace (12) to in turn heat segments of the fibres therein while these segments are in intimate side-by-side contact to a temperature sufficient to cause the fibre segments to fuse together. Drawings devices (22, 24) associated with the clamp units (14, 16) longitudinally draw the heated fibres while in the hot furnace to cause each fused fibre to develop a biconical taper and so form a coupler.

Abstract: Compounds of the formula I:R.sup.+[.sup.99m TcNX.sub.4 ].sup.- Iwherein R.sup.30 represents a cation and X represents a halo group, are prepared by reaction with an azide compound in the presence of a hydrohalic acid. The compounds are useful in production of .sup.99m Tc-labelled radio-pharmaceuticals by reaction with ligands and monoclonal antibodies or antibody fractions.

Abstract: A conducting composition for detonators having insensitivity to one amp of current or one watt of power comprising 40 to 80 parts by weight of lead styphnate 2 to 10 parts by weight of carbon black or graphite and the balance being lead oxide. Firing times of less than eight milliseconds can be achieved where at least one percent of graphite is included in the composition.

Abstract: Cheese curd suitable for conversion into natural hard cheese is prepared by ultrafiltering and diafiltering milk or a milk product to produce a retentate, ripening the retentate by fermenting with a cheese starter culture, coagulating the retentate to produce a coagulum, cutting, cooking and agitating the cut coagulum to produce curd, and separating the curd from whey. The retentate has a concentration Factor of 2-8 and contains 1.0-6.2% w/w lactose. Ripening the retentate produces a pH drop of 0.05-1.5 units. Cutting the a coagulum is at a time between 120% and 220% of coagulation time and cooking is at a temperature of 30.degree.-50.degree. C. Combined cooking and agitating operations take 20-120 minutes. Coagulation may be continuous, and a minor portion of the retentate may be separated, fermented with a cheese starter culture and mixed with the remaining retentate to produce a ripened retentate having a pH of 0.05-1.0 units lower than before ripening.

Abstract: The effectiveness of electronic earmuffs is improved by incorporating a mechanism which causes the middle ear muscles to contract before an intense sound is generated. This contraction is achieved by incorporating a wireless receiver into the earmuff. Immediately prior to the generation of the intense sound, the wireless receiver receives a signal which causes it to generate a loud, non-damaging sound in a loudspeaker in the earmuff. The received signal is generated by a radio frequency transmitter that is activated immediately prior to the activation of the mechanism producing the intense sound. The non-damaging loud sound from the loudspeaker causes the middle ear muscles to contract (this is a natural reflex of the ear). The intense sound is received outside the earmuff before the reflex contraction of the middle ear muscles has been relaxed.

Abstract: A method of fabricating a fused fibre optic coupler includes disposing two or more segments of optical fibre under longitudinal tension. The tensioned fibre segments are preheated to a temperature sufficient to soften the segments and thereby substantially relieve their tension by inelastic stretching of the segments. After the segments have cooled, the fibre segments are re-tensioned and then heated while in intimate side-by-side contact to a temperature sufficient to cause the fibre segments to fuse together.

Abstract: Apparatus for the control of growth of epitaxial alloy films onto a substrate. A uniformity measurement probe scans the growing film and controls a corrector gun directing a corrector beam to the film. The probe and gun are correlated to determine the relevant characteristics of a point on the growing film and to apply a particular correction. Possible deposition alloys are cadmium, mercury and tellurium with the corrector beam being selected from one or more of these specie.

Abstract: Compounds of the formula I:R.sup.+ [.sup.99m TcNX.sub.4 ].sup.- Iwherein R.sup.+ represents a cation and X represents a halo group, are prepared by reaction with an azide compound in the presence of a hydrohalic acid. The compounds are useful in production of .sup.99m Tc-labelled radio-pharmaceuticals by reaction with ligands and monoclonal antibodies or antibody fractions.

Abstract: A transmission delay line including a helical channel (2) formed in the surface of a cylinder (1), with a conductive sleeve (7) fitted to the cylinder to close the channel. A helical conductive member (4) is positioned within the channel (2) and spaced from the walls thereof by a dielectric material (5, 9).

Abstract: A distributed array hydrophone comprising an array of hydrophones each comprising a ceramic doublet assembly of hollow radially oppositely polarized members end held in a bobbin by decoupling means, the bobbins being linearly interconnected by semiflexible spacing members, the array being encapsulated in a vibration transmitting potting medium in a tube formed of a pressure-wave transmitting medium.

Abstract: Compounds of the formula I:R+[.sup.99m TcNX.sub.4 ]- Iwherein R+ represents a cation and X represents a halo group, are prepared by reaction with an azide compound in the presence of a hydrohalic acid. The compounds are useful in production of .sup.99m Tc-labelled radio- pharmaceuticals by reaction with ligands and monoclonal antibodies or antibody fractions.

Abstract: A cellular floating-point serial pipelined multiplier arranged to accept two synchronous digit serial data streams in floating-point format and to output one identically formatted stream is the floating-point product of the synchronous input members. The multiplier includes a delay circuit (1) for the X operand and a digit re-ordering/delay circuit (2) for the Y operand connected to a pipelined addition circuit (3) which outputs the product through a delay cell (6). A MODE control signal propagation and generation circuit (4) is also connected to the pipelined addition circuit (3) and to the digit re-ordering/delay circuit (2), and a cell differentiation circuit (5) is connected to control the pipelined addition circuit (3) and the digit re-ordering/delay circuit (2) and the X operand delay circuit (1).

Abstract: A method and device for removing undesired jammer signals from desired signals which comprises forming a beam on the desired signal in an adaptive antenna array characterized by an orthogonalizer array (12) to receive digitized signals from the antennas, and pass signals to a beamforming array (14) and including a late jammer canceller array (16) and an intelligent controller (24) arranged to control weights (W) and select a row having the desired beamformed signal.

Abstract: A method and apparatus for the control of growth of epitaxial alloy films onto a substrate. A uniformity measurement probe (5-6) scans the growing film and controls a corrector gun (9) directing a corrector beam (8) to the film. The probe (5-6) and gun (9) are correlated to determine the relevant characteristics of a point on the growing film and to apply a particular correction. Possible deposition alloys are cadmium, mercury and tellurium with the corrector beam being selected from one or more of these specie.

Abstract: A three-dimensional systolic architecture for beamforming according to convolve signals from an array with sets of weighting coefficients using a one dimensional array of similar modules with finite impulse response filter elements with outputs directed into pipelining register stacks and propagated to the stack boundaries for summing in accumulator arrays and demultiplexing.

Abstract: The method of measuring the optical scattering co-efficient of the ocean by means of a laser beam (15) from a platform (16) above the ocean surface (3) in which an ocean penetrating beam (15) is swept across the direct path of travel to the surface of the ocean (3) and through it to the ocean bottom (4) to be back-reflected to the ocean surface (3) and to a receiver on the platform (16) characterized by changing the field of view to alternately use a small and a large field of view and calculating from the larger field of view an estimate of the absorption co-efficient and from the smaller field of view an estimate of beam attenuation co-efficient.

Abstract: Sensing means for speed and direction of movement of a body (10) movable in an ambient fluid in a direction transverse to the longitudinal axis (11). A central chamber (16) has a plurality of radial bores (15) extending to the outer surfaces (12) and opening at their outer ends to the ambient fluid so that as the body (10) moves, a pressure differential between the inner ends (18) and the outer ends (17) causes fluid flow in the passages (15). Flow sensing means comprises a sound source and sound receivers (21) associated with respective bores (15) is provided to determine the phase shift caused by the fluid flow in each bore and hence determine the direction and speed of fluid flow. Processing means (32) determines the speed and direction of movement of body (10).

Abstract: Plasma generator which is constructed and operated to provide an enhanced probability of collisions between charged and neutral particles in the working chamber together with enhanced energy transfer and uniformity of the plasma. The plasma generator includes a chamber (1) with means to produce electrons (5) and to cause the electrons to rotate and spiral (6,7) to produce ion of gases introduced into the chamber to produce a plasma. The plasma is contained by magnetic mirrors (10,11) at each end of the chamber (2). Axial oscillation of the plasma is produced by a low frequency oscillating potential (9) in the chamber to significantly increased ion electron interaction.

Abstract: A method of and an apparatus for applying 3 or 4 point bending to a specimen of a material. The apparatus comprises bending members to contact the specimen, a drive system coupled to at least one of the bending members to cause relative vertical movement between the bending members to deflect the specimen, and a microprocessor interfaced with the drive system to control the operation of the drive system in accordance with a computer programm. The method is characterized by controlled monitoring of the actual experimental conditions applied to the specimen and varying of the operation of the drive system when the actual experimental conditions diverge from the required experimental conditions.