Abstract: A fascine capable of conforming to the contours of a supporting surface, comprises a core of loose cylindrical pipes disposed within a surrounding sleeve of similar pipes transversely and continuously inter-connected by flexible ties. Binding straps attached to the sleeve are reeved so as to cause axial pleating of the sleeve when tensioned, thereby to bind the core into rigid cylindrical form. The fascine is transported in bound condition and the binding straps slackened on deployment.

Abstract: A sliding breech block suitable for rapid, semi-automatic operation of a bag charge gun comprises two interlinked portions mutually engageable in two dispositions at a stepped interface one of the portions being drivable in a transverse guideway by gun runout via a crank and a shaft, and the other portion being guidable by rollers engaged in cam tracks to follow a semi-arcuate path aligned at one end with the gun barrel axis and at the other with the guideway axis.

Abstract: An apparatus for transferring television pictures onto cine film which operates independent of field scan frequency and which synchronizes each frame of the cine film with the television field scans to avoid the appearance of a bar across each frame. The apparatus comprises a cine camera which in operation is placed in front of a television screen and which generates a shutter opening signal, a control unit which synchronizes that signal with the video signal to the television such that the shutter opens at the beginning of a field scan, and a motor drive unit which utilizes the video signal to drive the camera shutter blade at one third the field scan frequency. The apparatus is useful for transferring television field scans operating at any frequency onto cine film.

Abstract: A fuel tank largely filled with a plurality of discrete impermeably walled cells, the cells and the space between them and the tank sides and roof being substantially filled with fire protective reticulated structure. The cells are each plugged into one of a plurality of fuel collection networks, via non-return valves which prevent return flow of the fuel into the cells. The region between the cells and the tank walls is arranged to receive incoming fuel which then flows from the ullage into the cells, and, by means of a self switching pump, is also arranged to empty preferentially. The purpose of the invention is to minimize fuel loss and fuel fire in the event of a tank rupture.

Abstract: A decompression bubble detector comprises a pulsed ultra-sound transmitter/receiver which is scanned across a cross-section of tissue and the total number of pulse echoes received in a preselected time interval is recorded. Changes in the total number of pulse echoes recorded in successive time intervals are used to monitor the decompression. A single transducer is scanned by means of a driven eccentric cam and a cam follower. A sin/cos potentiometer generates a signal related to the angular position of the transducer connected to a delay so that pulse counting can be arranged to coincide with the passage of the transducer across the target.

Abstract: A radio communications system for aircraft, particularly useful at UHF frequencies and in aircraft travelling at high speed and low level where rapid phase and amplitude fluctuations degrade intelligible speech transmission. The system comprises a transmitter in a first aircraft, the transmitter including an upshift frequency translator for transferring the frequency band of an input signal from a microphone to a higher band, and further including an amplitude modulator for modulating the frequency translated signals; and a receiver in a second aircraft arranged to receive and demodulate the transmitted signals, the receiver including a high pass filter for removing noise from the demodulated signal, and a downshift frequency translator for transferring the frequency band of the filter output to a lower band.

Abstract: A time delay and integrate signal processing device is provided to which, in use, a clock signal having a duty cycle which varies linearly with time at a predetermined rate is applied at an input. The number of delay stages in the path of signals from a plurality of input taps is determined in accordance with a predetermined function of the rate of change of the clock duty cycle.Embodiments of the invention may be employed to advantage in SONAR applications where signals are received from a plurality of transducers to scan a sector by constructive summation of signal returns. The predetermined function may be chosen to minimize distortion during a scan and so scanning may take place at a higher rate than with prior art devices enabling full coverage of the sector with good range resolution to be achieved with a single device.

Abstract: In a method of fabricating semiconductor devices, eg infra-red charge coupled devices (IRCCDs), the invention relates to the provision of a region containing a first species of ionized dopant with a body of semiconductor material in which the device is being fabricated, in which diffusion of this ionized dopant creates an internal electric field which provides a barrier against the penetration of a second relatively faster-diffusing species of ionized dopant into a selected region of the semiconductor body. In the method described in its application to the fabrication of a monolithic IRCCD, the second species of ionized dopant is introduced into detector regions of the body of semiconductor material to render them sensitive to infra-red radiation, and the barrier provided by diffusion of the first species of the ionized dopant serves to prevent the penetration of the second dopant species into the active charge storage and transfer channels of the CCD.

Abstract: A Panel Breaking Apparatus comprising at least one fusible conductor having at least one region of increased fusibility and embedded in intimate contact with the panel material and connected to a source of electrical power operable to produce a high-energy pulse of current sufficient to fuse the conductor and thus to break the panel.

Abstract: An acoustic wave device comprises a substrate carrying two or more acoustic components aligned in different directions and electrically connected together in parallel. The phase slope of the acoustic components are similar but their temperature coefficients of delay are different whereby their resultant frequency response is compensated over a useful temperature range. The acoustic components may be delay line employing surface waves or surface skimming bulk waves, or one or two port resonators using surface waves.

Abstract: A novel liquid crystal compound has the molecular structure: ##STR1## where R is an alkyl group, which may contain up to 18 carbon atoms and which may be normal or branched and may contain a chiral center, ##STR2## is a bicyclo (2.2.2) octane ring, --X-- is and Y is a cyano group CN or R.sup.1 or OR.sup.1 where R.sup.1 has the same definition as R.The compound may be used in mixtures with other liquid crystal compounds in the same or other families and the compound or mixtures may be used in known liquid crystal devices, eg the twisted nematic and cholesteric-to-nematic phase change devices, depending on its properties.

Abstract: A liquid crystal compound having the formula: ##STR1## where X is --CH.sub.2.CH.sub.2 -- or CH.sub.2 OY is ##STR2## and R is a straight or branched (possibly chiral) alkyl group having up to 15 carbon atoms.

Abstract: Apparatus for degrading safety fuel of the type containing an anti-misting polymer and comprising a bank of interfitting stators and rotors with a plenum chamber at some station along the bank, whereby rotation of the rotors will cause safety fuel pumped through the apparatus to be subjected to sufficient shear and local acceleration to be degraded to a state acceptable for engines and their control apparatus.

Abstract: This disclosure relates to the packaging of microwave integrated circuits (MICs) whereby an MIC is hermetically sealed within an enclosure comprising a first plate of dielectric material which carries the circuit to be enclosed, a wall of dielectric material sealed to the surface of the first plate surrounding the circuit, and a second plate of dielectric material providing a lid sealed over the wall to complete the enclosure. The first plate carries planar conductors which define at least one microwave transmission line, e.g. microstrip, extending across the wall into the enclosure from outside to provide direct microwave coupling to the enclosed circuit and thereby obviating the usual need for transitions to and from coaxial cable.Part or all of the enclosed circuit may be contained within a recess provided by forming an aperture in the first plate and sealing a third plate of dielectric material across the aperture from below.

Abstract: Liquid crystal materials are provided which are esters having the general formula: ##STR1## where n has the value 1, 2 or 3 and R is a normal or branched chain alkyl containing up to ten carbon atoms and preferably four to ten carbon atoms.These materials display a cholesteric mesophase and also a chiral smectic C mesophase underlying the cholesteric mesophase. Both of these mesophases are thermochromic.

Abstract: In order to improve the resolution and performance of an imaging device comprising an elongate strip of photconductive semiconductor material having first and second current electrodes and an associated read-out electrode the strip is modified so that generated photocarriers are caused to drift in a flow path in which their diffusive spread in the longitudinal direction, from the first electrode to the second electrode, is limited to a spread substantially less than the diffusion length characteristic of the material. In particular the strip may be modified by a plurality of fine interdigital slots extending alternately from opposite sides of the strip and which, in at least a terminal region adjacent the second electrode, are spaced apart by a distance less than the diffusion length.The device may be used in either a scanned, or a stationary, image system.

Abstract: A process for the production of 2, 2', 4, 4', 6, 6'-hexanitrostilbene, which gives a readily isolable product and in which solvent recovery is relatively straightforward, is described.An alkali or alkaline earth hypochlorite was reacted with 2, 4, 6-trinitrotoluene in an aqueous organic solvent, preferably containing tetrahydrofuran. The reactant mixture was allowed to stand for at least 30 minutes when a solution of a mineral acid, especially sulphuric acid, was added, with stirring, to acidify the mixture to a final pH of less than 5, preferably between 0.5 and 1.0, especially 0.7. This acidification caused agglomeration of the hexanitrostilbene. When complete mixing of the solutions had been obtained, the stirring was stopped and the mixture allowed to settle and separate into two layers. The top layer, which contained little solid product, was run off through a filter and the filtrate was treated separately to recover solvents, especially tetrahydrofuran.

Abstract: A liquid crystal material having a low threshold voltage for use in displays comprises a mixture of at least three liquid cyrstal materials at least two of which are selected from the following compounds. ##STR1## or the above compounds where in a cyclo hexane ring is substituted for one of the benzene rings, where X is a short alkyl group C.sub.n H.sub.2n+1 and n is an even integer, or where X is a short alkoxy group C.sub.m H.sub.2m+1 and m is an odd integer.

Abstract: A surface acoustic wave device comprises a quartz substrate having a flat surface carrying one or more transducers for launching and receiving surface acoustic waves along a track in the flat surface. In this invention the flat surface lies in a plane rotated about a Y axis by plus or minus 41.degree. to 47.degree. from the Z plane and the track is aligned 61.degree. to 67.degree. from the Y axis.

Abstract: The Leukocytosis Promoting Factor (LPF) of Bordetella Haemagglutinin (HG) is separated from crude cell supernatant or partially purified protein by affinity chromatography on a column material consisting of an insoluble polymeric support to which is bound a sialoprotein (glycoprotein containing sialic acid) or other substance rich in sialic acid.The sialoprotein was preferably a plasma sialoprotein, such as haptoglobin or ceruloplasmin, or a salivery mucin, and the polymeric support was preferably an agarose gel, though other conventional supports could be used.By this process, on treatment of an ammonium sulphate precipitated extract, the haemagglinating activity may be increased 300-600 fold over the extract and 10,000 times over the crude centrifuged cell supernatant. Alternatively a fraction substantially free from LPF-HG may be collected.