Showing papers by "Newcastle University published in 1971"
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TL;DR: This article surveys the work that has been done on the treatment of deadlocks from both the theoretical and practical points of view.
Abstract: A problem of increasing importance in the design of large multiprogramming systems is the, so-called, deadlock or deadly-embrace problem. In this article we survey the work that has been done on the treatment of deadlocks from both the theoretical and practical points of view.
787 citations
TL;DR: The original work of Gale and Shapley on an assignment method using the stable marriage criterion has been extended and the algorithm derived is proved to satisfy all the conditions of the problem.
Abstract: The original work of Gale and Shapley on an assignment method using the stable marriage criterion has been extended to find all the stable marriage assignments. The algorithm derived for finding all the stable marriage assignments is proved to satisfy all the conditions of the problem. Algorithm 411 applies to this paper.
343 citations
TL;DR: In this article, a method of digital simulation of different configurations of driers for agricultural materials is proposed, based on the thin-layer drying rate for the material, the heat and mass balance in the drier and the rate of heat transfer from the air to the stock.
266 citations
TL;DR: It is suggested that, in the absence of pituitary or hypothalamic disease, the response of serum T.R.S.H.H., or synthetic thyrotrophin-releasing hormone, provides a simple, safe, sensitive, and reliable test of thyroid function.
250 citations
TL;DR: It has been established that the behaviour of skin is not portrayed by the simple laws of friction, but by a more complex relationship of the type F =μWn, probably because skin is subject to viscoelastic rather than purely plastic deformation.
Abstract: SUMMARY.— The coefficient of friction has been determined for skin and various materials. It has been established that the behaviour of skin is not portrayed by the simple laws of friction, but by a more complex relationship of the type F =μWn. This is probably because skin is subject to viscoelastic rather than purely plastic deformation. Friction may be altered by the type of material in contact with skin and is further influenced by surface lubrication. Dry talcum powder reduces friction slightly for certain materials against skin, but increases friction when it becomes wetted.
236 citations
TL;DR: New electrophysiological techniques have demonstrated a loss of motor units in muscular dystrophy and myasthenia gravis; the sizes of the surviving motor units suggest that both diseases result from disordered function of motoneurones.
168 citations
TL;DR: In this paper, the results of fieldwork and laboratory studies on weathered rocks mainly from the Dart-moor area, S.W. England, are given, and the results show clear trends of decreasing strength and fracture spacing with increased weathering and general conclusions and observations on engineering weathering classifications have been drawn.
Abstract: Summary Weathering and weatherability have been defined and a general scheme of weathering classification has been developed for engineering. Fundamental mechanical changes in behaviour due to weathering are considered for both intact rock and discontinuous rock, and a brief study is made of available field and laboratory tests to assess weathering and weatherability. From this, suggestions are made for classification schemes designating rock quality for mapping and core logging. The results of fieldwork and laboratory studies on weathered rocks mainly from the Dart-moor area, S.W. England, are given. Several different rock types, including granite, dolerite, limestone and mudstone, have been classified on the weathering scale, tested in the field by point loading and Schmidt hammer, and laboratory determinations of strength and porosity made. The results show clear trends of decreasing strength and fracture spacing with increased weathering and general conclusions and observations on engineering weathering classifications have been drawn. In early stages of weathering it appears that there is a general increase of fractures per unit volume and in later stages of weathering there is a rapid increase in chemical decay. In addition, geometrical distributions of weathering in fold and fault situations have been examined. The full implications of Tertiary warm climate weathering and Quaternary cold climate weathering are not yet clear.
154 citations
TL;DR: In this paper, radiometric age determinations of three Jurassic igneous formations in South Morocco carry a stable component of magnetic remanence, giving a mean palaeomagnetic poleposition at 61° S, 71° E, A95= 14°.
Abstract: Summary
Samples collected from three Jurassic igneous formations in South Morocco carry a stable component of magnetic remanence, giving a mean palaeomagnetic pole-position at 61° S, 71° E, A95= 14°. Two of the formations were situated in the stable Saharan Shield region, and one within the Central High Atlas fold-belt. There is no systematic difference between the pole-positions derived from these two regions of contrasting tectonic history, and furthermore, no significant difference between the mean Jurassic pole-position for Morocco and that for South-east Africa. It is concluded that no significant post-Jurassic relative motion has occurred between NW and SE Africa.
Two of the formations studied were previously thought to be Upper Palaeozoic, but radiometric age determinations presented in this paper give consistent values of between 181 and 187 My. These results indicate the occurrence of a widespread episode of Jurassic igneous activity, producing structures which frequently parallel the coastline, and are possibly related to the break-up and dispersal of the fragments of Pangaea during the Mesozoic.
129 citations
TL;DR: The need for caution is indicated in concluding that large groups of muscle fibres of one histochemical type in human limb muscles necessarily indicate denervation and subsequent reinnervation.
124 citations
TL;DR: In this article, the effect of an uneven bottom on the long gravity waves is investigated by using a nonlinear perturbation method, to the lowest order of perturbations, for the free-surface elevation h (1) :
Abstract: Effect of an uneven bottom on the long gravity waves is investigated by using a nonlinear perturbation method. The following simple nonlinear equation is obtained, to the lowest order of perturbation, for the free-surface elevation h (1) : \(\frac{\partial h^{(1)}}{\partial\eta}+c_{1}h^{(1)}\frac{\partial h^{(1)}}{\partial\xi}+c_{2}\frac{\partial^{3}h^{(1)}}{\partial\xi^{3}}-c_{3}\frac{\mathrm{d}B}{\mathrm{d}\eta}h^{(1)}{=}0\), where ξ and η are stretched space-time coordinates, and the coefficients c 1 , c 2 and c 3 are all functions of the bottom surface B (η). If the bottom is flat (d B /dη=0), the equation reduces to the well-known Korteweg-de Vries equation. It is interesting to note that, due to the presence of the last term, damping or instability may occur depending upon the sign of the local slope, d B /dη, of the bottom. A comment is given on the relationship between the conventional shallow-water (or long-wave) theory and the present analysis.
TL;DR: In this paper, the authors described the production of non-stoichiometric titanomagnetites in a water slurry followed by oxidation in air at temperatures <300 °C.
TL;DR: It is confirmed that lower oesophageal temperature readings will give an approximate indication of the cerebral temperature in the absence of an open thorax or a rapid transfusion of cold blood.
Abstract: It is confirmed that lower oesophageal temperature readings will give an approximate indication of the cerebral temperature in the absence of an open thorax or a rapid transfusion of cold blood. Nasopharyngeal readings are less reliable and should not be used on their own. Middle and upper oesophageal recordings are unsatisfactory because of ventilatory cooling. For an assured accuracy greater than ± 1.0°C, direct intracerebral readings are necessary. The brain at a depth of 4 cm is usually slightly warmer than the lower oesophagus or nasopharynx. More superficial readings may be affected by the ambient temperature and surgical procedures
TL;DR: It can be shown that specimens of Mya subjected to low salinities greatly increase the rate of loss of ammonia from their bodies, but no comparable increase occurs in excreted sulphate ions, which might be expected from the degradation of taurine, not in taurines itself.
Abstract: Publisher Summary Taurine is not only an oxidative end product but also a key intermediate of sulfur metabolism. In marine invertebrates it appears to have three organic functions. It can be shown that specimens of Mya subjected to low salinities greatly increase the rate of loss of ammonia from their bodies. However, no comparable increase occurs in excreted sulphate ions, which might be expected from the degradation of taurine, not in taurine itself. Thus, it could be that sulphate ions are retained in the body or possibly might be attached to mucopolysaccharides and disposed of by enhanced mucus secretion. The other known functions are concerned with transphosphorylation, this particularly in marine polychaetes, and with the rate of transmission of nerve impulses and the ionic balance of nerve axoplasm. Taurine also had a specific activity similar to alanine and together with aspartic acid, proline, and glycine makes up most of the concentration of amino derivatives present.
TL;DR: In this article, a simple two-stage model was proposed for the formation of gas bubbles at a plate orifice submerged in an inviscid liquid, applicable at high gas injection rates.
TL;DR: Although numerous changes in the chemical constituents of blood and urine have been observed in patients with muscle diseases, the biochemical abnormalities can be adequately studied only by a direct investigation of the diseased muscle.
Abstract: Publisher Summary Voluntary muscle disease can result from a variety of causes. Muscle diseases can be divided and subdivided according to their etiology. Many are very rare and have not yet been the subject of biochemical investigations. The major biochemical efforts have been directed toward the genetically determined myopathies, especially the muscular dystrophies and, to a lesser degree, the myotonic disorders and some of the more common muscle disorders of established neurogenic origin. Although numerous changes in the chemical constituents of blood and urine have been observed in patients with muscle diseases, the biochemical abnormalities can be adequately studied only by a direct investigation of the diseased muscle. It is difficult to procure a sufficient number of samples of biopsied muscle from patients. The tissue donated is often from relatively advanced cases, where the degree of muscular degeneration is so extreme as to mask the earlier and more meaningful changes. The recognition of Duchenne type muscular dystrophy in the very early stages by serum enzyme changes is of some help in this respect, but the provision of adequate quantities of suitable muscle is still a difficulty.
TL;DR: Calcium regulation in normal and calcium-depleted snails has been investigated and a comparison is made between the mechanisms of sodium regulation and calcium regulation in L. stagnalis.
Abstract: 1. Calcium regulation in normal and calcium-depleted snails has been investigated. 2. L. stagnalis has an uptake mechanism with a high affinity for calcium ions and shows a positive calcium balance in media containing more than 0.062 mM Ca/l. 3. Influx and net uptake of calcium are related to external calcium concentration in a non-linear manner. The uptake mechanism is half-saturated and near-saturated in external media containing 0.3 and 1.0-1.5 mM Ca/l respectively. 4. Calcium uptake from external concentrations of less than 0.5 mM Ca/l is against a small electrochemical gradient whereas from external concentrations greater than 0.5 mM Ca/l there is no adverse gradient. 5. Calcium depletion does not significantly alter the normal influx or net uptake rate of calcium from 1.0 mM Ca/l. 6. The calcium concentration in the blood remains constant during net uptake from, and net loss to, the medium. 7. A comparison is made between the mechanisms of sodium regulation and calcium regulation in L. stagnalis .
TL;DR: In this paper, the current state of knowledge of vortex streets behind circular cylinders in the Reynolds number range 50 to 160 is discussed, and a brief experiment confirming the existence of the transition is described.
Abstract: A discussion is given of the current state of knowledge of vortex streets behind circular cylinders in the Reynolds number range 50 to 160. This was prompted by Gaster's (1969) report that he could not find the transition at a Reynolds number of about 90 observed by Tritton (1959) and Berger (1964a). A further brief experiment confirming the existence of the transition is described Reasons for rejecting Gaster's interpretation are advanced. Possible (mutually alternative) explanations of the discrepant observations are suggested.
TL;DR: In this paper, the effect of drying and ensiling ryegrass on the site of digestion of the energy and carbohydrate fractions was studied in sheep fitted with rumen cannulas and re-entrant can-nulas in the proximal duodenum and terminal ileum.
Abstract: 1. The effect of drying and ensiling ryegrass on the site of digestion of the energy andcarbohydrate fractions was studied in sheep fitted with rumen cannulas and re-entrant can-nulas in the proximal duodenum and terminal ileum.2. The sheep were given fresh (frozen) grass, dried grass, wilted and unwilted silage pre-pared from herbage harvested from the same sward. The grass diets were offered twice dailyto each animal and paper impregnated with chromium sesquioxide was administered twicedaily into the rumen. Twenty-four hour collections of duodenal and ileal digesta, adjusted togive 100 yo recovery of Cr2O3, were analysed to determine the extent of digestion in the fore-stomachs, the small intestine and the caecum and colon.3. Total digestibility of the gross energy was similar for the fresh grass, dried grass andwilted silage diets (67·4,68·1 and67·5 %)but higher for the unwilted silage (72·0 %, P < 0·01).There was an increased flow of energy into the small intestine when the sheep were given driedgrass and unwilted silage. The proportion of the apparently digested energy lost within thesmall intestine was greater when the dried grass was given (302 yo) than when the fresh grasswas given (23·6 yo).4. Drying or ensiling of wilted material affected digestion neither in the entire alimentarytract nor in the different sections of the tract, of some carbohydrate fractions. About 97 yo ofthe digested water-soluble carbohydrate, over 90 yo of the digested cellulose and over 70 yo ofthe digested hemicellulose were digested before reaching the small intestine. The increasedamount of energy entering the duodenum of the sheep given the dried grass was notaccounted for by changes in the fate of these carbohydrate fractions in the digestive tract. Withunwilted silage, digestibilities of the cellulose and hemicellulose fractions were higher, andlower proportions of the digested carbohydrates were lost before the small intestine.
TL;DR: The results suggest that the enzyme has two inhibitor sites, one for leucine and one for valine, and that maximum efficiency of inhibition is achieved when both sites are filled.
TL;DR: A reconstruction of Gondwanaland linking India, Australia and Antarctica and fitting these against Africa is compared with some geological and geophysical observations and also with the recent reassembly proposed by Smith and Hallam.
Abstract: A reconstruction of Gondwanaland linking India, Australia and Antarctica and fitting these against Africa is compared with some geological and geophysical observations and also with the recent reassembly proposed by Smith and Hallam. The probable history of the disintegration and movement of the northern and southern continents into their present configuration is assessed against the available palaeomagnetic data.
TL;DR: In this paper, a mathematical treatment of the effect of thermal distortion on the thermal contact resistance between two semi-infinite solids of different materials is given, and it is shown that problems of this type sometimes have no steady state solution and this is attributed to the discontinuous nature of the boundary condition for thermal contact.
TL;DR: Reaction times were shorter when the two signals were presented each to different hemispheres compared with presentation of both signals to the same hemisphere and ‘same’ than for ‘different’ judgements.
TL;DR: In this paper, the effect of iron and nickel impurities on the development of microporosity during the gasification of 850°C polyfurfuryl alcohol carbon with carbon dioxide has been investigated.
TL;DR: This study was undertaken to remedy a deficiency in the investigation of a population in the industrial north-east of England, which showed a pronounced secular tren,d to earlier maturation and little in the way of variation from one region to another.
Abstract: In the last 20 years have appeared several studies of current age at menarche in Britain, which show a pronounced secular tren,d to earlier maturation and little in the way of variation from one region to another. The majority of these surveys however relate to the southern part of England, and there has been no investigation of a population in the industrial north-east. This study was undertaken to remedy this deficiency.
TL;DR: Poly-isoprenols have been demonstrated to participate in the synthesis of O-antigen1, peptidoglycan2, 3 and mannan4, and all these membrane lipids so far isolated and identified have been shown to be the C55 polyisopreol, undecaprenol, although it has not yet been demonstrated that they are the same isomer.
Abstract: THE pathways for the formation of several bacterial wall polymers have been thoroughly investigated. In some cases it has been shown that the biosynthesis involves the participation of lipid intermediates that are concerned with the transfer and transport through the membrane, of sugar residues and related components from intracellular nucleotide precursors to polymer chains in the wall. All these membrane lipids so far isolated and identified have been shown to be the C55 polyisoprenol, undecaprenol, although it has not yet been demonstrated that they are the same isomer. Thus poly-isoprenols have been demonstrated to participate in the synthesis of O-antigen1, peptidoglycan2, 3 and mannan4.
TL;DR: Ionic movements into and out of the starved salt-depleted fourth instar larvae of Aedes aegypti have been studied during independent uptake of Na + and Cl - to find out how these movements are balanced electrically by a loss of K + or Cl.
Abstract: 1. Ionic movements into and out of the starved salt-depleted fourth instar larvae of Aedes aegypti have been studied during independent uptake of Na + and Cl - . 2. About 33% of the Na + taken up from Na 2 SO 4 is balanced electrically by a loss of K + , about 49% is exchanged for H + , and about 17.5% is accompanied by SO 4 -2 . 3. About 36% of the Cl - taken up from KCl is presumably balanced electrically by a loss of unknown and possibly organic ions, about 41% is exchanged for HCO 3 - (and possibly OH - ) and about 23% is accompanied by K + .
TL;DR: In this paper, the role of closed pores is emphasised and a model of the activation process is developed which enables the closed pore volume of carbon to be determined without assuming a value for the density of the carbon in the pore walls.