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By W. J. Whiten, D. W. Grinsberg

Most cluster analysis techniques are not well suited to the analysis of engineering data as they have been designed for more qualitative data that tend to produce compact clusters. A clustering technique is described which develops and uses local cluster shapes to build clusters that are suitable for use in engineering applications. The technique is finding application in the analysis of many types of data, particularly where multiple trends and outlying points occur in multiple dimensions. Applications of particular interest are the calibration of on-stream analytical equipment and the analysis of data on plant performance. In both cases the multidimensional nature of the data renders manual analysis very difficult

Dec 1, 1991

By G Williams

Discussing equipment, systems of work, the need for updated programmes of local seismic exploration, and developments within the South Wales coalfield.

Jan 1, 1993

By C. C. Harris

The use of Alyavdin's equation Y(x,t) = 1-e(-bt) for describing the effect of grinding time on size distribution is discussed. The equation transforms into linear form by expressing it as log-log reciprocal (1 - Y) versus log t. For plotting, specially divided grids are available; Rosin-Rammler or Weibull charts may be used. The data of Herbst and Fuerstenau are especially useful for illustrating the Alyavdin-Weibull chart in two applications: (1) presenting data (which are relatively unaffected by experimental scatter) and comparing them with theoretical predictions, and (2) as a test for the zero-order kinetics production hypothesis. The chart based on the Alyavdin-Weibull equation is suggested as a useful aid in the analysis of kinetic data (/ versus f), though not as a procedure in its own right. Proposed applications are (1) displaying data with excellent clarity, since it avoids the kind of congestion inherent in some other plotting methods, and (2) as a test for assumed kinetic relationships. Sometimes, equation 1 describes the data quite closely, and in these cases the parameter values appear to be related to certain operating conditions.

Dec 1, 1971

By G W. Clamp

The most traum atic event within the lUK coal industry during the last 30 years was its privatisation. Who were the relatively unknown people from RJB: white knights or robber barons? This paper highlights the strong safety and progressive engineering cultures th at existed and continues within the company. A long-term view of the business coupled with proven professionalism is amply developed. Quite dearly, to revert to private ownership is not a return to Victorian values but ‘back to the future’.

Jan 8, 1997

By P Cochrane

Our ability to generate information and transport it about the planet on super highways of optical fibre is about to change the way in which we communicate, work and live. There is not a single aspect of our future that will go untouched by the communication and computing revolution that Is now upon us. The change we are about to witness will overshadow the impact of the printed word, industrial revolution and physical transport. The next major wave of information technology (TT) development will focus on the delivery of information and experience on demand, in the right form, at the right time, at the right price, to fixed or mobile terminals anywhere, over networks of optical fibre, radio, satellite and optical wireless. Bandwidth, distance and time will no longer be significant cost elements as service and access become dominant.

Jan 7, 1996

By D G. Oldfield

Pall has developed and supplied to several airlines cabin air libers to provide clean air for passengers and crew in flight, while reducing airline operating costs. Most of today's modern commercial passenger aircrafts employ cabin air recirculation as a means of reducing operating costs. With large numbers of passengers being subject to an increasing proportion of recirculated air for hours at a time, the matter of cabin air quality, with particular respect to the health effects on passengers and crew, has to be addressed. Commercial pressure will ensure that the airlines and aircraft manufacturers will not revert back to the total fresh air systems of the 1960s and 1970s. In fact, feasibility studies are already being undertaken to look at increasing the proportion of recirculated air to 80% and above. With the application of specialist nitration technologies. Pall is able to ensure that the requirements for economy are met whilst ensuring that the air is effectively rendered as 'fresh air’ each time it is recirculated.

Jan 9, 1996

By M. Thompson, B. Coles, M. Hale

The use in regional geochemical reconnaissance of replicate analysis of natural coatings of iron and manganese oxides on the surface of pebbles in stream sediment is described. Pebble coatings were selectively analysed for their relative contents of absorbed trace elements by ablating a small quantity of the coating with a laser beam and sweeping the aerosol obtained into an inductively coupled plasma atomic emission spectrometer. Using this procedure, a geochemical survey in northwest Wales revealed anomalous concentrations of Cu, Mo, As, Zn, Cd, Pb and Co in the pebble coatings of streams draining the mineralised Coed-y-Brenin diorite and the Dolgellau gold belt.

Jan 4, 1992

For the convenience of those who are unfamilar with thermodynamics, the following brief description and explanation is given of the thermodynamical terms and methods used in this book. It must, however, be strongly emphasized that the account given below is not an introduction to chemical thermodynamics; its sole purpose is to give the reader a rough understanding of the methods used in the earlier chapters. For further information, reference must be made to the standard textbooks on chemical thermodynamics by Glasstone.

Jan 1, 1953

By C. E. Dunn

Paper presented at the 28th International Geological Congress held in Washington DC, July 1989 (International geochemical mapping sessions). Evidence is accumulating that reconnaissance-level biogeochemical sampling can provide valuable insight into the chemistry of the substrate. Problems such as seasonal variations in plant chemistry and the lack of a universal biogeochemical sample medium may be circumvented by adopting normalising procedures. The planet can be divided into a few climatic zones, each of which is characterised by one or two common plant genera. If it can be demonstrated that the chemical differences between certain species of a single genus are small - as is suggested by studies of boreal forests - it would seem feasible to apply biogeochemistry as a low-density geochemical mapping tool. The technique could prove particularly useful for assessing the substrate chemistry of areas of dense forest, rugged terrain and difficult access by employing airborne sampling of trees from helicopters

Jul 1, 1991

Discussion following the presentation at the North of England Institute of Mining and Mechanical Engineers' general meeting held in Newcastle-upon-Tyne, 8th April 1916, included the author's introduction, written contributions by Bedson P.P., Gregory T.W.D. and Morgan J.D., oral contributions by Louis H., Greener T.Y. and Severs W., and the author's reply

Dec 1, 1916

By A. Hemami

In order to automate the operation of mechanical loaders it is essential to have a knowledge of the forces that act on the bucket and of the trajectory that the bucket should follow. A trajectory for the cutting edge of a bucket is derived from studies of the forces acting during the scooping phase. The proposed trajectory has a minimum energy consumption and is simple to automate. It is determined initially by setting to zero certain components of the resistive forces to the bucket motion which would otherwise result in unnecessary work and consequent energy wastage. The method for finding the appropriate trajectory is discussed on the basis of the properties of the material to be loaded and the loader size.

Jan 4, 1993

By B. H. Smith

"Most of the discoveries of nickel sulphide deposits in Western Australia have followed the search for gossans. The chances of further discoveries depend on improving our understanding of the cover of strongly leached and transported materials that obscure approximately 85% of the area of the Yilgarn Block that has nickel sulphide mineralization potential. The lateritic profiles that are observed on the Yilgarn Block today were formed over a period of more than 100 m.y. of warm and humid climates. This lateritized land surface has been preserved by induration during subsequent arid climates as well as by the structural stability of the Yilgarn Block.In geochemical surveys of lateritied terrain samples have to be taken from at least the saprolite zone usually by drilling so that confident predictions can be made of the significance of analytical data. Account must be taken of the mineralogy of samples, as well as the nature of the horizon of a laterite profile that is being sampled, owing to the concentrating effects on trace elements of Fe and Mn oxides.Multivariate techniques have been applied successfully to analytical data in gossan recognition when textural evidence is ambiguous. Pathfinder geochemistry has also been used in gossan recognition and the most significant recent advance has come from studies of platinum group metals in nickel sulphides and their dispersion during weathering."

Jan 1, 1984

By N. T. Moxon, D. Mead, S. B. Richardson

A laboratory and theoretical study of air decks was carried out to assess the effects of the size and location of air-decks on fragmentation. The degree of fragmentation was found to depend on both factors. As the size of the air-deck increases the degree of fragmentation is reduced relative to a full column charge. However, the reduction is relatively small until a critical size is exceeded. The critical size depends on the strength and structure of the surrounding material. A critical air-deck length of 30-35% of the original explosive column was determined for the model materials used in the study. A theoretical explanation of the results was derived based on pressure decay rate relationships. The location of the air-deck also influences fragmentation. The interaction and oscillation of the two shock fronts from the top and bottom charges mean that mid-column air-decks produce better fragmentation for the same air-deck length and explosive loading as top-column or bottom-column air-decks.

Jan 4, 1993

By S A. M Crawshaw, J A. B Fortune

Trackless battery powered haulage vehicles have been in operation in British coal mines principally for longwall face transfer and personnel transportation. Changes within the industry have resulted in the introduction of room and pillar coal mining methods and the introduction of increasingly heavier longwall roof supports This has resulted in the introduction of: • Battery powered coal haulage machines, which, without the need for trailing cables, increase productivity within room and pillar mining. • Battery powered longwall shield haulers which are capable of carry ing the heaviest shield supports currently being utilised within the British coal mining industry. The conventional machines have been adapted from an American design to meet the requirem ents of European legalisation. This has seen the- emphasis being placed upon the supplier with the European M achinery Directive being introduced, necessitating the assigning of a 'C E ' m ark to each vehicle. Battery vehicle technology has advanced to meet the demands of the ever changing market and will no doubt he further adapted to meet the requirement of the British coal mining industry.

Jan 10, 1996

By Stainier X.

The connexion between the Kent and the Continental coalfields on the one hand and the western British coalfields on the other has been for many years a controversial subject between geologists. These coalfields were once considered as detached portions of a former extensive sheet of Carboniferous deposits, but some geologists seem now to incline to the view that they were never connected. The writer hopes to show that the problem is one of the most difficult of geological investigations; that we are still far from a perfect solution; and that both of the extreme theories must be set aside. The physiography of NW Europe during the Carboniferous, with its various generations of earlier folds, is outlined and the features of the Lower and Upper Carboniferous anticlines and synclines discussed, followed by consideration of the denudation of the coalfields and local descriptions of the Malvernian range and Usk anticline, the Pennine chain, the Shropshire coalfield and the Kent coalfield. An attempt is made to trace the transverse Midland anticlines southwards and to deal with the intervening syncline: for example, if the dissymmetrical profile of the Pennine Chain holds good at its southern end then the syncline west of the chain must be deeper than the syncline east of it (the Kent syncline), and in this syncline the deepest part must be at its south-eastern corner, and therefore south of the diagonal ridge. T here is some actual evidence of the existence of Coal-Measures in this syncline, as the results of the Batsford and Burford borings prove. The hypothetical character of most of the conclusions will prove, beyond any doubt, how fa r geologists still are from a perfect settlement of this problem, and how much this settlement is dependent on the more or less advanced state of knowledge regarding all the geological features of these coalfields and of the surrounding country

Dec 1, 1916

Jan 1, 1947

By Fearnsides W. G.

The map shows the sites of collieries and important boreholes in the district, with approximate underground contours of the pre-Permian surface of the Coal-Measures and of the Barnsley Bed

Dec 1, 1916

By B. Denby

sintered ores, to be removed by a pneumatic,

Apr 1, 1995

By Marshall Charles Riddell, John Carlon

local news

Jan 12, 1997

By D. F. Ball, P. R. Dawson, J. T. Fitton

Report of discussion at December, 1970, IMM general meeting (Chairman: M. J. Cahalan, President) and contributed remarks on the paper published in Transactions/Section C (Mineral Processing & Extractive Metallurgy), vol. 79, September, 1970, pp. C189-96, plus the authors' replies. Contributors included Cohen E., Hope B., Wasse D.G., Shakespeare A.G., Burwood D.S., Jones H.A., Dartnell J., Carter G.C., Henderson T.A., Relf G. and Clark S.W.

Dec 1, 1971