Showing papers by "City University London published in 1983"
TL;DR: In this paper, the authors investigated the kinetics of methane oxidation over palladium and platinum catalysts supported on a number of metal oxides using a pulse-flow microreactor technique.
332 citations
TL;DR: Methods previously adopted and problems encountered in assessing and evaluating quality of life in clinical studies of cancer are reviewed and desirable properties of any such assessment methods and approaches to the analysis ofquality of life data are discussed.
Abstract: After brief consideration of the definition of the term ‘quality of life’, methods previously adopted and problems encountered in assessing and evaluating quality of life in clinical studies of cancer are reviewed. Desirable properties of any such assessment methods and approaches to the analysis of quality of life data are discussed.
Illustrations are provided by reference to the methods of assessment of quality of life incorporated in two recently-initiated studies of cancer treatment.
198 citations
TL;DR: In this article, an upper limit of 10-42 cm-2 is placed on the absolute value of the cosmological constant by comparing with the prediction of the perihelion shift of Mercury.
115 citations
TL;DR: In this paper, an analysis of the steady states of two-dimensional convection near threshold in a laterally finite container with aspect ratio 2L [Gt ] 1 is presented, which involves an expansion of the hydrodynamic equations in the small parameter [(R − R0)/R0]½, and leads to amplitude equations with boundary conditions, which generalize to higher order those previously obtained by Newell & Whitehead and Segel.
Abstract: An analysis is presented of the steady states of two-dimensional convection near threshold in a laterally finite container with aspect ratio 2L [Gt ] 1. It is shown that the allowed wavevectors which can occur in the bulk of the container are reduced from a band |q| ∼ [(R − R0)/R0]½ in the laterally infinite system to a band |q| ∼ (R − R0)/R0 in a system with sidewalls (R is the Rayleigh number and R0 its critical value in the infinite system). The analysis involves an expansion of the hydrodynamic equations in the small parameter [(R − R0)/R0]½, and leads to amplitude equations with boundary conditions, which generalize to higher order those previously obtained by Newell & Whitehead and Segel. The precise values of the allowed wavevectors depend on the Prandtl number of the fluid and the thermal properties of the sidewalls. For certain values of these parameters all the allowed wavevectors are less than the critical value q0. The applicability of the results to convection in a rectangular container is briefly discussed.
112 citations
TL;DR: In this article, the authors focus on the chemistry of excited complexes and the maximum rate for the process is determined by the rate constant for diffusion control in the solvent employed, which is a function of the number of collisions that must occur within the lifetime of the excited state.
Abstract: Publisher Summary This chapter focuses on the chemistry of excited complexes. The term exciplex (excited complex) is used to describe an electronically excited molecular complex of definite stoichiometry. Complexes falling into this broad classification include excimers (excited dimers) (electronically excited complexes formed between identical atoms or molecules), heteroexcimers (electronically excited complexes formed between two non identical atoms or molecules), and excited charge-transfer complexes (complexes produced by excitation of ground state molecular complexes for which there is conclusive evidence for association in the ground state). The formation of intermolecular complexes in fluid solution requires that after excitation of one of the partners, collision with the other partner must occur within the lifetime of the excited state. The maximum rate constant for the process is determined by the rate constant for diffusion control in the solvent employed.
108 citations
TL;DR: A detailed investigation of the environments in which velar stops are fronted by a phonologically delayed child reveals that fronting is dependent on both word stress and word boundaries; that it shows lexical exceptions; and that it occurs in output only.
81 citations
TL;DR: The methodology in operation is illustrated by application to the formulation of a model of the human cardiovascular system, its neural control and the effect of drugs.
Abstract: Mathematical models are powerful tools for investigating and understanding complex systems. Their use must be guided by knowledge of their potentialities and limitations and a well-based approach to the modelling process. Such is embodied in an integrated methodology for model formulation, identification and validation which has emerged from practical modelling as well as historical studies. The methodology in operation is illustrated by application to the formulation of a model of the human cardiovascular system, its neural control and the effect of drugs. The derivation of the model is described in depth and a complete model listing is given. The companion paper develops a validation methodology and applies it to the cardiovascular model.
70 citations
TL;DR: In this paper, the authors discuss some of the advantages and limitations involved in the use of thermoanalytical measurements to elucidate selected aspects of the constituent processes involved during the combustion of an organic polymer.
70 citations
TL;DR: The results imply that rats do not invariably approach a localizable appetitive Pavlovian conditioned stimulus but that stimulus-approach responses depend on the nature and modality of the conditioned stimulus.
Abstract: Two experiments investigated autoshaping in rats to localizable visual and auditory conditioned stimuli predicting response-independent food. In Experiment 1 considerable conditioned-stimulus approach behavior was generated by a localizable visual conditioned stimulus that was situated approximately 35 cm from the food tray. Using the same apparatus in Experiment 2 we found that the conditioned-stimulus approach was generated only to a visual conditioned stimulus and not to a localizable auditory conditioned stimulus even though subjects (1) could discriminate presentations of the auditory conditioned stimulus, (2) had associated it with food, (3) could localize it, and (4) would approach the auditory stimulus if this behavior constituted an instrumental response to food. The predominant conditioned responses to the auditory stimuli were goal tracking (entering the food tray) and orienting towards the food-paired conditioned stimulus by head turning and rearing and turning. These results imply that rats do not invariably approach a localizable appetitive Pavlovian conditioned stimulus but that stimulus-approach responses depend on the nature and modality of the conditioned stimulus.
63 citations
TL;DR: In this paper, a thermal analysis of complete systems, including the polymeric substrate, and comprehensive studies (e.g. by triangular diagrams) of the flammability is presented.
54 citations
TL;DR: A set of criteria is proposed for the comparison of software reliability models to provide a logically organized basis for determining the superior models and for the presentation of model characteristics.
Abstract: A set of criteria is proposed for the comparison of software reliability models. The intention is to provide a logically organized basis for determining the superior models and for the presentation of model characteristics. It is hoped that in the future, a software manager will be able to more easily select the model most suitable for his/her requirements from among the preferred ones.
TL;DR: In this article, fire retardance and smoke suppression were studied in three systems containing acrylonitrile-butadiene-styrene terpolymer, decabromobiphenyl, and commercial metastannic acid.
01 Jun 1983
TL;DR: In this paper, the authors investigated the flammability and smoke-forming tendency of systems containing widely varying proportions of an acrylonitrile-butadiene-styrene terpolymer (ABS), decabromobiphenyl (DBB) and anhydrous aluminium(III) oxide, (b) aluminium oxide monohydrate and (c) aluminium trihydrate.
01 Jan 1983
TL;DR: It is suggested that users are interested solely in the quality of predictions which can be obtained from software reliability models and some predictions are extremely poor: notably those arising from ML analysis of the Jelinski-Moranda model.
Abstract: We suggest that users are interested solely in the quality of predictions which can be obtained from software reliability models. Some ways of analysing the quality of predictions are proposed and several models and inference procedures are compared on real software failure data sets. We conclude that some predictions are extremely poor: notably those arising from ML analysis of the Jelinski-Moranda model. Others seem quite good. We suggest promising areas for future work.
TL;DR: In this article, the authors present a systematic analysis of all available neutrinoxF3 data, using an analytic parametrisation which incorporates second order QCD predictions for Q2 evolution.
Abstract: We present a systematic analysis of all available neutrinoxF
3 data, using an analytic parametrisation which incorporates second order QCD predictions forQ
2 evolution. We find
$$\Lambda _{\overline {MS} } = 0.30 \pm 0.13{\rm{ }}GeV$$
where the error is statistical, and both Fermi andW-boson propagator corrections have been made to the data. Neglect of the former has negligible effects, but neglect of the latter would increase Λ by ∼0.1 GeV. We find that higher-twist effects are small and negative, and estimate their effect on the determination of Λ. We are unable to fit the data with higher-twist terms alone.
TL;DR: In this article, the authors considered thermal driven flows in a 2-dim rectangular cavity filled with a fluid-saturated porous medium, where the applied temperature gradient is perpendicular to the gravity vector.
TL;DR: In this article, the pyrolysis of cellulose was carried out at high heating rates and at temperatures up to 823K, and the results showed that virtually no char is formed and the major gaseous products are the carbon oxides.
TL;DR: The experiment described here showed that in a free-recall paradigm in which each list word is embedded in a continuous stream of subject-vocalized distractor activity, recency recall was greater when the words were presented auditorily rather than visually.
Abstract: Gardiner and Gregg (1979) showed that in a free-recall paradigm in which each list word is embedded in a continuous stream of subject-vocalized distractor activity, recency recall was greater when the words were presented auditorily rather than visually. The experiment described here showed that this auditory advantage persisted even when list and distractor items were both spoken at a controlled pace by the experimenter, and that it was little influenced by instructions to give priority in recall either to the beginning or to the end of the list. These results strengthen the conclusion that this effect cannot be accommodated by any echoic memory theory and, because the effect was not enhanced when prerecency items were recalled first, demonstrate an additional difference between it and the somewhat similar auditory advantage found in immediate recall.
TL;DR: In this article, the CAARC Standard Model (CAARC) was tested in a simulated atmospheric shear flow and the model was mounted on two mutually perpendicular pairs of torsion bars with linear mode shapes; external electromagnetically controlled damping was applied.
TL;DR: The two papers support the thesis that mathematical models, used wisely, are effective and necessary tools in complex systems research.
Abstract: Model valadity is a multi-faceted concept which is expressed as a set of validity criteria related to different modelling objectives. These criteria form the basis of a validation methodology for biological models - an integral part of the modelling methodology presented in the preceding paper. This is applied to the model of the human cardiovascular system. By means of model decomposition and reconstruction, validation occurs at a number of levels and includes empirical, theoretical and heuristic tests. In general, the model is shown to have reasonable validity in terms of its objectives; it is an adequate representation of the human cardiovascular system under certain conditions. Although some defects may be traced to the modelling of neural control, the model has an important role in the conception and testing of different hypotheses for such control. In conclusion, the two papers support the thesis that mathematical models, used wisely, are effective and necessary tools in complex systems research.
TL;DR: Volume and price inflationary pressures on publishers have probably been responsible for other changes in journal characteristics between 1900 and 1970 such as increased printing density and number of words and characters per journal per year.
Abstract: The readability of scientific papers has decreased dramati cally in the past 100 years, but now appears to have bottomed out at the ' very difficult' level. Volume and price inflationary pressures on publishers have probably been responsible for other changes in journal characteristics between 1900 and 1970 such as increased printing density and number of words and characters per journal per year.
Abstract: There is often a need for the lighting engineer to apply results of visual experiments, conducted under laboratory conditions, to normal viewing situations. But whereas the latter implies use of the eye's natural pupil, the former may well employ a smaller, artificial pupil. The effect of this on luminance level is discussed and conversion tables are provided.
TL;DR: In this paper, it is shown that both corner flows have a double structure with the outer layers being convection dominated, and numerical integration, with spectral decomposition, is shown to lead to values of the core mass flux that are in good agreement with existing experimental data.
Abstract: Cavity flows driven by an applied horizontal temperature gradient are encountered in a variety of industrial and environmental situations. Determination of the core structure, away from the flow boundaries, depends strongly on the corner behaviour of the vertical boundary layer equations. An analysis of these corner zones is given for flows in which both the Rayleigh number and the Prandtl number are large. It is shown that both corner flows have a double structure with the outer layers being convection dominated. The consequences of the analysis for the core mass flux, a much debated question in the literature, are discussed. Numerical integration, with spectral decomposition, is shown to lead to values of the core mass flux that are in good agreement with existing experimental data.
TL;DR: In this article, the authors consider the problem of using the expected utility approach to war termination in the context of the ending of the Boer War and explain why an expected utility-based approach has difficulty in accommodating the fact that there was a long delay between the initiation of certain proposals for termination and the eventual acceptance of essentially the same terms.
Abstract: The article considers the problem of using the expected utility approach to war termination In the context of the ending of the Boer War, the authors attempt to explain why an expected utility approach has difficulty in accommodating the fact that there was a long delay between the initiation of certain proposals for termination and the eventual acceptance of essentially the same terms They conclude that the problem in this case was that neither of the decision maker was unitary, and that the process of formulating a preference ordering takes time It is of course reasonable in a static theory to ignore this However, to apply the process of decision-making as distinct for just the end result, we need a theory of the process of preference formulation in groups
TL;DR: In this paper, a modified Taylor problem with the fluid flowing between a rotating inner circular cylinder and an outer stationary surface whose radius is a constant plus a small and slowly varying function of the axial co-ordinate z is considered.
Abstract: We consider a modified Taylor problem, with the fluid flowing between a rotating inner circular cylinder and an outer stationary surface whose radius is a constant plus a small and slowly varying function of the axial co-ordinate z. This variation is chosen in such a way that the flow is locally more unstable near z=0 than near z=±∞, so that Taylor vortices appear more readily near z=0. The theory is developed to show how vortices of strength varying with z develop as the speed of rotation is increased through a critical value which is a perturbation of the classical value. Wave number changes in the axial direction are also calculated.
TL;DR: In this paper, the effect of variable viscosity and viscous dissipation for heated developing laminar flows in circular tubes have been investigated, covering a comprehensive range of input data for the case of constant wall heat flux.
TL;DR: In this paper, the combustion of cellulose using high heating rates and at temperatures up to 823K with varying concentrations of oxygen in the atmosphere was studied and it was shown that the gaseous products are the same as those formed in the absence of oxygen and the carbon oxides are again the major components.
TL;DR: In this article, the authors reviewed problems of education and training in measurement and instrumentation, and the work of IMEKO in this field, among the principal topics discussed is the nature, scope and organisation of measurement and instruments science.