Ilford Limited

Craley Group Limited

Michael John Parker

William E Long

Anthony Martin Lannon

Terence C Webb

A fluid pipeis monitored using a distributed acoustic sensing (DAS) fibreprovided within pipe. The DAS fibreis coupled at one end to a light emitterand a light detector. The light emitteremits light pulses into the DAS fibre. The light detectordetects backscattered light so as to provide an indication of the vibration experienced by each section of the DAS fibreand thus of vibration characteristic of particular pipe events including leaks of the pipe. The DAS fibrein a pipecan also be used to locate the route of a buried pipeby successively tamping the ground surface at a number of locations A-E in the vicinity of the suspected route of the pipeand comparing the tamping vibrations detected from each location A-E.

Monitoring of fluid pipes

A pipe liner has an elongate duct of thin laminated thermoplastic layers and remains relatively flexible and folded to a flat form. In this form, opposing sides of the duct are pressed into close proximity aided by folding of the duct, so the liner can be stored efficiently. In use, the liner is inserted into a pipe. The liner is subsequently heated and pressed against the inner surface of the pipe to form a close fit. Once the liner cools, it sets in place providing a close fitting pipe lining. In order to ensure adequate and even heating of the pipe liner during installation, heating is provided within the liner. The heating may comprise: a plurality of conductive filaments; electromagnetic susceptor material; or a plurality of magnetic particles.

Pipe liners and the installation thereof

Processing of monochrome photographic silver halide print material

There is described a photographic developing solution which comprises as an image toning agent a compound of formula I: ##STR1## where Ar is an aromatic or heteroaromatic ring which may be substituted, in a concentration of at least 0.00035 moles/liter.

Toning of photographic print material

There is described a concentrated photographic silver halide developing solution which comprises from 50 to 150 g/liter of an ascorbic acid type compound of the general formula I: ##STR1## or alkali metal salts thereof, in which the group R represents a hydroxylated alkyl group, and at least one basic compound the anion of which is carbonate, sulphite or hydroxide of which the cation is an alkali metal, especially sodium or potassium, the total sodium to total potassium ion ratio in the concentrated developing solution being from about 50:50 to 0:100 (mole: mole). Preferably the concentrated solution is entirely aqueous but it may comprise a proportion of water-miscible organic solvents such as ethyl alcohol, or glycol solvents.

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Cheshire, United Kingdom

Michael John Parker