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The purpose of this paper is to explore the factors that affect the compactness of the mud filter cake, so as to prepare diaphragm wall slurry with good uniformity, small filtration loss and excellent recycling performance.

In this paper, the thickness, filtration loss and slurry viscosity of the filter cake are used as the characterization methods. The effects of pore depth, slurry specific gravity, intercalated metal ions, bridging polymer and water-soluble polymer on the compactness of the filter cake were studied.

The experimental results showed that the slurry's own pressure (pore depth) and specific gravity have little influence on the compactness of the filter cake and K⁺ can be considered as an auxiliary filtration loss reduction factor. Both the sulfonate copolymer and the potassium polyacrylate particle can significantly reduce the filtration loss of the slurry, which can effectively improve the filter cake compactness. Moreover, the composite application of potassium polyacrylate particles in the sizes of 80–100 and 150–200 meshes can exhibit a better filter cake compaction effect.

It solves the problems of high pulping cost, serious pollution of the environment, poor quality of filter cake formation and large filtration loss during the construction of the diaphragm wall, which improved the construction quality of the diaphragm wall.

This paper aims to analyse the effect of soft soil grouting on the deformation of the closed shield tunnel with the measured data.

Combining the measured data of vertical, horizontal and convergence deformation of the adjacent tunnel during the grouting construction in foundation pit engineering, the influence of grouting on metro tunnel in soft soil area is analyzed.

The researches indicate that early grouting has the main effect on the horizontal displacement of the tunnel; Due to the disturbing effect of the uninterrupted grouting construction on the soil and the transfer pressure of the rheological soil to the bottom of the tunnel, the tunnel is obviously lifted; And the convergence deformation of the tunnel increases caused by the overburden pressure in the vertical direction, so that the tunnel appears the phenomenon of staggered seam, large opening of bolted joint, damaged segment even leakage of water.

The study based on the field monitoring data is rarely reported, especially the topic about inadvertent grouting in soft soil area is likely to cause severe deformation of adjacent metro tunnel.

Hand‐operated Acid Pump. The TK/HODP hand‐operated diaphragm acid pump is a portable unit suitable for works duties such as the emptying of carboys. The pump can be operated by unskilled labour, is self‐priming and can accept a wide range of acids, alkalis, abrasive and corrosive liquors. Hose connections and pump housings are in Petrox ‘C’ ceramic material, and diaphragms are available in either rubber or Hypalon.

Examines the wide range of liquid and solid level sensors, their technologies and commercial application.

Provides background information on trends in level sensing, on how each type works and the various applications. Some selection criteria are given.

There is a wide range of level sensors for every target liquid and solid sensing application, but the sector is technologically mature. There are some new application areas deriving from legislation and climate change.

Provides information of value for those involved with sensor applications.

I am delighted that the fifth Corrosion and Metal Finishing Exhibition has been brought to Leeds and I congratulate the sponsors and exhibitors on their decision to stage this Exhibition in the heart of the industrial north.

Reviews piling methods and their possible effects, mainly during construction, on adjacent structures, noting that piling falls into two basic types: displacement, where the material is forced into the ground, and replacement, where the ground is removed and replaced with concrete or grout. Examines the merits and demerits of their various applications.

Optoacoustic spectroscopy is a completely new technique for the examination of solid and liquid samples and a system for this is now commercially available in the UK in the form of EDT's Model OAS 400 Opto‐Acoustic Spectrometer. This attrac‐tive instrument has been developed at EDT Research, 14 Trading Estate Road, London NW10 7LU, with the backing of the National Research Development Corporation from the pioneering work in the field by Dr G. F. Kirkbright of Imperial College, London. The principles of OAS rest on the fact that light absorbed by a solid sample is converted to heat with the sample. If the sample is sealed in a small cell containing a gas e.g. air or nitrogen the heat will be transferred to the gas and cause it to expand. If the incident light beam is now chopped at a steady rate, the gas in the cell will be alternately heated and cooled leading to a series of pressure pulses which can be detected by microphone. Scanning the wave‐length of the light and recording the associated sound amplitude leads to an absorption spectrum analogous to that of more conventional methods of spectrometry. The advantages of OAS lie in the fact that spectra of opaque substances, powders, polymers, suspensions and slurries can be made without difficulties arising from lack of transmission, scattering or reflection.

Much to the relief of everyone, the general election has come and gone and with it the boring television drivel; the result a foregone conclusion. The Labour/Trade Union movement with a severe beating, the worst for half a century, a disaster they have certainly been asking for. Taking a line from the backwoods wisdom of Abraham Lincoln — “You can't fool all the people all the time!” Now, all that most people desire is not to live easy — life is never that and by the nature of things, it cannot be — but to have a reasonably settled, peaceful existence, to work out what they would consider to be their destiny; to be spared the attentions of the planners, the plotters, provocateurs, down to the wilful spoilers and wreckers. They have a right to expect Government protection. We cannot help recalling the memory of a brilliant Saturday, but one of the darkest days of the War, when the earth beneath our feet trembled at the destructive might of fleets of massive bombers overhead, the small silvery Messerschmits weaving above them. Believing all to be lost, we heaped curses on successive Governments which had wrangled over rearmament, especially the “Butter before Guns” brigade, who at the word conscription almost had apoplexy, and left its people exposed to destruction. Now, as then, the question is “Have they learned anything?” With all the countless millions Government costs, its people have the right to claim something for their money, not the least of which is the right to industrial and domestic peace.

Now available from George Meller Ltd, the Sofraser on‐line viscometer has been designed to provide continuous accurate data on most fluids up to a viscosity of 10 6cP.

The new Mastersizer X, recently launched by Malvern Instruments, is an extended specification version of its Mastersize family of laser diffraction particle size analysers.