Showing papers by "City University London published in 1980"
TL;DR: In this paper, the principal processes by which sulphur compounds are emitted into the atmosphere are reviewed in the light of the most recent data, and comparisons are made between the man-made emissions calculated on a per unit area and a per capita basis for the whole Earth and for some industrialized countries.
242 citations
TL;DR: In this article, the steady states of two-dimensional convection in a laterally finite rectangular container near threshold were analyzed and it was shown that the presence of sidewalls severely restricts the allowed wave vectors which can occur in the bulk of the container.
Abstract: An analysis is presented of the steady states of two-dimensional convection in a laterally finite rectangular container near threshold. It is shown that the presence of sidewalls severely restricts the allowed wave vectors which can occur in the bulk of the container. This effect provides a possible mechanism to explain the observed wavelength increase of convective rolls with increasing Rayleigh numbers.
67 citations
TL;DR: In this article, the proportion of recalled words recognized was found to be much higher than expected on the basis of this relation when lists composed of pairs of abstract words or digit word pairs were presented under typical study conditions of the recognition failure paradigm.
61 citations
TL;DR: The model has been adapted to include cyclic ventilation, dead space, shunt, and a separate muscle compartment and matched both steady state and dynamic results from man breathing increased CO 2 concentrations.
52 citations
TL;DR: In this paper, the electrochemical oxidation and reduction of hydrogen and chlorine in hydrochloric acid has been investigated on graphite, ruthenized titanium and platinum electrodes using steady state and potentiostatic pulse methods.
Abstract: The electrochemical oxidation and reduction of hydrogen and chlorine in hydrochloric acid has been investigated on graphite, ruthenized titanium and platinum electrodes. Both steady state and potentiostatic pulse methods were used. Cell studies were also carried out in cells with flow-by and flow-through chlorine electrodes. Results indicate that the electrode kinetics are fast and the electrolysis and fuel cell reactions can be carried out in the same cell with electric-to-electric efficiencies in excess of 75% at current densities of 300 mA cm−2. Mass transfer limitations at the chlorine electrode during discharge can be eliminated by cell pressurization and the use of flow-through electrodes.
44 citations
TL;DR: Research supports the notion that problems of dynamic binocular vision and control while reading are important, and indicates that the group retarded in reading indicated a significant relationship between anomalies ofynamic binocular viewing and their reading attainment.
Abstract: Summary. The visual behaviour under both static and dynamic viewing conditions was examined in a group of 13-year-old successful readers, compared with a group of the same age retarded in reading. Each group was video recorded reading aloud, without sound, a passage on the Neale Analysis that was well within their capacity to read. Criteria for selection and experimental controls are described. Each group was assessed for letter chart visual acuity, and examined on the full range of tests on a standard vision screener. The range of fusion that could be obtained before binocular vision broke down was assessed using polarised vectographs. Each pupil was asked whether vision tended to become double when reading. Dynamic visual behaviour, ocular control, and associated postural compensation and muscular stress while actually reading were investigated. The data obtained from these static and dynamic tests were then compared for the successful and retarded reading groups. It was found that the group retarded in reading indicated a significant relationship between anomalies of dynamic binocular viewing and their reading attainment. On the tests under static viewing only one significant difference—poor stereopsis—could be found between the two groups. Research supports the notion that problems of dynamic binocular vision and control while reading are important.
29 citations
TL;DR: In this paper, the complete two-dimensional partial differential equations for developing laminar flow in a circular tube have been treated by a finite difference analysis, and the analysis predicts the complete developing hydrodynamic and thermal fields, together with friction factors and heat transfer coefficients.
Abstract: The complete two-dimensional partial differential equations for developing laminar flow in a circular tube have been treated by a finite difference analysis. Property variation with temperature, especially that of viscosity, is allowed for in a flexible manner. The continuity and momentum equations, and then the energy equations, are solved by direct elimination at each axial step, and marching procedure used in the axial direction. A new technique is that the stepwise energy balance is rigidly satisfied throughout by using it as a constituent equation in place of the ‘explicit’ wall thermal boundary condition normally used.
The analysis predicts the complete developing hydrodynamic and thermal fields, together with friction factors and heat transfer coefficients. It has been tested for a range of fluid velocity and thermal boundary conditions and for various fluids, including high viscosity oils, water and air.
Data for constant wall heat flux have already been published. 1,2 Predictions for constant wall temperature presented here are for forced and combined convection and are compared with experimental data of Test3 and Zeldin and Schmidt4.
26 citations
TL;DR: The complex Pt(SO2)2(PPh3)2 reacts with butadiene and isoprene to give the complexes Pt(1,2-η-C4H5R) and PPh3(R = H or Me) which, on refluxing in benzene, afford high yields of the triangulo-cluster compound Pt3(µ-Ph)3, characterised by a single crystal X-ray diffraction study as discussed by the authors.
Abstract: The complex Pt(SO2)2(PPh3)2 reacts with butadiene and isoprene to give the complexes Pt(1,2-η-C4H5R)(SO2)(PPh3)2(R = H or Me) which, on refluxing in benzene, afford high yields of the triangulo-cluster compound Pt3(µ-Ph)(µ-PPh2)(µ-SO2)(PPh3)3, characterised by a single crystal X-ray diffraction study.
22 citations
TL;DR: This paper examines some classical procedures in order to see when they can be given a Bayesian justification.
Abstract: The elimination of nuisance parameters has classically been tackled by variousad hoc devices, and has led to a number of attempts to define partial sufficiency and ancillarity. The Bayesian approach is clearly defined. This paper examines some classical procedures in order to see when they can be given a Bayesian justification.
21 citations
TL;DR: Examination of the titles of articles demonstrated that even after ten years there is no standard terminology in the energy analysis literature, which casts doubt on the value of searching by title terms for new interdisciplinary subjects.
Abstract: A bibliometric study on energy analysis literature is reported. The literature is characterised by heavy emphasis on English-language journal articles and reports, and, after an initial exponential growth rate, it is now growing more slowly. Examination of the titles of articles demonstrated that even after ten years there is no standard terminology in the area. This casts doubt on the value of searching by title terms for new interdisciplinary subjects. On the other hand, secondary services employing controlled-language indexing were found to index the articles under a variety of headings. In any case, coverage of the subject by secondary services is generally poor. There are no clear core journals for this subject area. Some recommendations are made on how both authors of papers in the field and secondary services can ensure better retrieval of energy analysis articles.
19 citations
TL;DR: There are two extracellular beta-lactamases produced by Bacillus cereus 569: one of these enzymes, beta- lactamase I, is inactivated by 6-beta-bromopenicillanic acid: the site of reaction is serine-44, and it becomes a good candidate for an active-site group in these enzymes.
Abstract: There are two extracellular β-lactamases produced by Bacillus cereus 569. One of these enzymes, β-lactamase I, is inactivated by 6-β-bromopenicillanic acid: the site of reaction is serine-44. This is a conserved amino acid residue in the other β-lactamases whose structures have been determined, and it becomes a good candidate for an active-site group in these enzymes. The inactivation may involve a rearrangement leading to a dihydrothiazine. The other extracellular enzyme produced by B. cereus , β- lactamase II, is exceptional in requiring metal ions for activity. The Zn II and Co II enzymes (the former is more active) have been studied by nuclear magnetic resonance, and by absorption spectroscopy. The groups that bind the metal ion required for activity are three histidine residues and the enzyme’s sole thiol group.
TL;DR: In this paper, the stability properties of the high Reynolds number flows of an incompressible fluid and their non-parallel stability properties in certain plane channels whose widths vary slowly in the streamwise direction are considered.
Abstract: Considered below are the high Reynolds number flows of an incompressible fluid, and their nonparallel stability properties, in certain plane channels whose widths vary slowly in the streamwise direction. The first approximation to the steady-state flow is governed by the classical boundary layer equations but with the pressure unknown. Solutions, some including separation and reattachment, to this are obtained numerically for a range of the parameters involved, and the stability of the resulting flows is considered using fixed frequency disturbances and taking into account the nonparallel nature of the basic flow by use of a W.K.B. method. The calculations yield critical Reynolds numbers, below which all the disturbances decay downstream, and for various Reynolds numbers above the critical values the growths of the small disturbances are calculated. The results are specialized to a particular class of channels which are straight far upstream and far downstream but vary in between. So the predictions should be much more easily amenable to experimental investigation and comparisons than those of the more idealized, diverging channel, flow problem studied by Eagles & Weissman [1] and the only other basic flow seriously studied from the viewpoint of nonparallel flow stability theory, the Blasius boundary layer. The results also represent the first application of both quasiparallel and slightly non-parallel stability theory to channels involving slowly varying but finite changes in width.
TL;DR: In this article, it was shown that the magnitude of triplet production is also dependent upon the orientation of the halogeno group with respect to the aromatic nucleus and the length of the chain and the nature of the hologeno group.
Patent•
31 Jan 1980TL;DR: A rotary forging or upsetting machine consisting of an upper platen and a lower platen is described in this paper, where the platen can be mounted on a carrier pivotable about an axis which passes through the point of intersection of the first and second axes.
Abstract: A rotary forging or upsetting machine comprising an upper platen and a lower platen, the lower platen being rotatable about a first axis and the upper platen being rotatable about a second axis which intersects the first axis, the upper platen being mounted on carrier which is pivotable about an axis which passes through the point of intersection of the first and second axes, means being provided for adjusting the angle of the upper platen while the platens are rotating, and means being provided for applying a force to the lower platen to move it towards the upper platen so that a workpiece carried by the lower platen is deformed by the upper platen moving around the workpiece.
TL;DR: In this paper, several variants of behavioural decision theory were employed to predict the occupational intentions of 79 final-year engineering students and found that several models succeeded in predicting significantly; that predictive power increased over the period; and that intentions predicted the job actually obtained.
Abstract: Several variants of behavioural decision theory were employed to predict the occupational intentions of 79 final-year engineering students. Questionnaires were administered at 2 weekly intervals for 14 weeks. It was found that several models succeeded in predicting significantly; that predictive power increased over the period; and that intentions predicted the job actually obtained. In addition, some support was obtained for an effect of outside events upon intention change; and also for this effect to be working through the mediating process postulated by decision theory. Certain implications of the data for student counselling were drawn, and support was obtained for the analysis of engineering in the United Kingdom proposed by the Finniston Report.
TL;DR: In this article, the reaction of [Pt2(µ-cyclo-octa-1,5-diene)(PEt3)4] with 5,6-dicarba-nido-decaborane affords 9-H-9,10,9,9-(Et3P)2-µ10,11,H-7,8,9-C2PtB8H10, which on pyrolysis (100 °C) loses H2 and forms 9 -H-H
Abstract: Reaction of [Pt2(µ-cyclo-octa-1,5-diene)(PEt3)4] with 5,6-dicarba-nido-decaborane affords 9-H-9,9-(Et3P)2-µ10,11-H-7,8,9-C2PtB8H10, which on pyrolysis (100 °C) loses H2 and forms 9-H-9,10-(Et3P)2-7,8,9-C2PtB8H9; the structures of these compounds have been determined by X-ray crystallography.
TL;DR: Extended Huckel molecular-orbital calculations are reported for the trigonal prismatic platinaboranes and carbaplatinaborane [B8Pt(PH3)2}H8]2, and the observed conformations of these molecules have been accounted for in terms of the nodal characteristics of the frontier orbitals of the constituent Pt(PH 3)2 and carbaborane fragments.
Abstract: Extended Huckel molecular-orbital calculations are reported for the trigonal prismatic platinaboranes and carbaplatinaboranes [B8Pt(PH3)2}H8]2– and [B6C2{Pt(PH3)2}H8], and the observed conformations of these molecules have been accounted for in terms of the nodal characteristics of the frontier orbitals of the constituent Pt(PH3)2 and carbaborane fragments. A description of the bonding in the less symmetrical isomer of [B6C2{Pt(PH3)2}H8] has been similarly derived from an analysis of the effect of transforming nido-[B8H8]2– into arachno-[B8H8]2–.
19 May 1980
TL;DR: It is instructive to look at some of the reasons advanced by software developers for their reluctance to use software reliability measurement tools.
Abstract: It is instructive to look at some of the reasons advanced by software developers for their reluctance to use software reliability measurement tools. Here are a few common ones:(A) "Software reliability models are statistical. Programs are deterministic. If certain input conditions cause a malfunction today, then the same conditions are certain to cause a malfunction if they occur tomorrow. Where is the randomness?"(B) "I am paid to write reliable programs. I use the best programming methodology to achieve this. Software reliability estimation procedures would not help me to improve the reliability of my programs."(C) "We verify our software. When it leaves us it is correct."(D) "I ran your software reliability measurement program on some data from a current project of ours. It said there was an infinite number of bugs left in the program. Who are you trying to kid?"(E) (same manager as in D, but one week later) "We corrected a couple of bugs and ran the reliability measurement program again. This time it said that there were 200 bugs left. Infinity minus two equals two hundred? Is this the new math?"(F) "We put a lot of effort into testing. The selection of test data is a systematic process designed to seek out bugs. Reliability estimation based on such test data would be no guide to the performance of the program in a use environment."(G) "We are writing an air traffic control program. Total system crash would be catastrophic. Other failures range from serious to trivial. Reliability models do'not distinguish between failures of differing severity."
TL;DR: In this article, three bonded joints in carbon fiber-reinforced plastic were analyzed by finite element methods to obtain the elastic stress distribution, and the joints had areas of high stress concentration.
TL;DR: In this paper, the reaction of [Co(PEt3)4] with closo-1,7-C2B6H8 or closo -1,5-C 2B3H5 affords, respectively, 2,2,2-(H)(Et3P)2-2,1,8-CoC2H5.
Abstract: Reaction of [Co(PEt3)4] with closo-1,7-C2B6H8 or closo-1,5-C2B3H5 affords, respectively, 2,2,2-(H)(Et3P)2-2,1,8-CoC2B6H8 and 2,2-(Et3P)2-2,1,6-CoC2B3H5, the structures of both complexes being established by X-ray crystallography.
TL;DR: In this article, it was shown that ω-(4-halophenoxy)alkyl bromides (Ia,b n=10) in methanol usually lead to preferential cleavage of the aryl-halogen bond and data supporting the conclusion that this occurs from the first excited single state.
TL;DR: In this article, the sine-Gordon equation can be reduced to a separable form via the use of a fifth Painleve transcendent, which can be expressed in characteristic coordinates.
TL;DR: In this paper, a discussion of the principle of causality and its role in the derivation of the Lorentz transformations of special relativity is presented. But the authors do not discuss the role of conformal groups in the description of space-time.
Abstract: This article contains a discussion of the principle of causality and its role in the derivation of the Lorentz transformations of special relativity; in particular, there is an exposition of a key theorem of E. C. Zeeman concerning the relationship between the causal group and the inhomogeneous Lorentz group. In addition there are several remarks on the interchangeability of the geometrical and algebraic modes of expression relating to space-time structure, and an explanation of the role of the conformal group in the description of space-time.
TL;DR: In this paper, the displacement problem of elastostatics in two dimensions is formulated in terms of integral equations via the Airy stress function, and the integral equations are solved numerically using piecewise constant approximations to the unknown functions.
Abstract: The displacement problem of elastostatics in two dimensions is formulated in terms of integral equations via the Airy stress function. The integral equations are solved numerically using piecewise constant approximations to the unknown functions. The validity of the formulation is demonstrated by its application to a simple problem with a known solution.
TL;DR: The connection between this isomorphism and the inertial relation on the state-space is explored, leading to more general statements, including a pseudo-homogeneous automaton is pseudo-isomorphic to a group-quotient automaton.
Abstract: Every cyclic automaton is isomorphic to a semi-group quotient automaton, while for a homogeneous automaton the semi-group may be replaced by a group. The connection between this isomorphism and the inertial relation on the state-space is explored, leading to more general statements. For example, a pseudo-homogeneous automaton is pseudo-isomorphic to a group-quotient automaton.
01 Jan 1980
TL;DR: This chapter explains programming in Fortran with a focus on programs written in detail on a minicomputer, which was necessarily of limited size.
Abstract: This chapter explains programming in Fortran. The programs written in detail in Fortran in this text were all run on a minicomputer and were necessarily of limited size. In operating the machine, the program tape or card deck is first fed into the computer, and under the influence of the control unit, the information on this tape is suitably stored. Thereafter, the data tape or card deck is fed in, and the numerical values of the parameters are stored in the locations preselected by the instructions of the program. For the computer to carry out this series of operations, they must be incorporated as a series of instructions in the computer program. The instructions have to be in a form that the computer circuits may readily follow; this is known as basic machine code and is in binary form. Unfortunately, such a code besides requiring a knowledge of the logic of the computer circuits is also extremely lengthy and tedious to formulate. A program written in Fortran consists of a series of relatively simple algebraic statements or instructions called the source program. This is then translated by the compiler into the basic machine code instructions and is then referred to as the object program.
TL;DR: In this article, the authors investigated the influence of hold-up on surge amplitude and wave speed in hydraulic transport of solid-liquid mixtures and concluded that holdup reduces the amplitude of surge pressures and that further studies are required to establish a suitable relationship between holdup ratio and both solids concentration and density ratio.
Abstract: The relatively high flow velocities encountered in the hydraulic transport of solid-liquid mixtures aggravates the problems of pressure surge phenomena under fault conditions as well as during normal system load changes. The paper presents the basic theory for estimating surge amplitudes and wave speeds and extends previous work by investigating the influence of hold-up. It is concluded that hold-up reduces the amplitude of surge pressures and that further studies are required to establish a suitable relationship between the hold-up ratio and both solids concentration and the density ratio. Nevertheless, favorable agreement has been found between the limited experimental data available and the theoretical model.
TL;DR: In this article, it was shown that the nonaffine conformal transformations of four-dimensional Minkowski spaces are necessarily global causality violators, and this fact was used to obtain an elementary group-theoretic proof of the theorem that the Lorentz group implies causality.
Abstract: We prove that the nonaffine conformal transformations of four-dimensional Minkowski space are necessarily global causality violators, and use this fact to obtain an elementary group-theoretic proof of the theorem that global causality implies the Lorentz group.
01 Jan 1980
TL;DR: In this paper, an on-line computer determination of optimum steady state operating conditions of industrial plant, where the optimal solution is computed using a mathematical model whose parameters are periodically updated by comparing model and real process measurements.
Abstract: The paper is concerned with on-line computer determination of optimum steady state operating conditions of industrial plant, where the optimal solution is computed using a mathematical model whose parameters are periodically updated by comparing model and real process measurements. A method is employed which, by iterating between parameter estimation and a modified system optimisation, attains the correct optimum steady state operating condition on the real process in spite of structural inaccuracies in the mathematical model. Results of computer simulation studies are presented on the application of the iterative technique to on-line determination of maximum net rate of return from an exothermic chemical reactor in which optimum raw material input flow and reaction temperature controller set points are computed using a simplified steady state mathematical model. Particular attention is given to the effects of real process dynamics and measurement errors, and the simulation results illustrate the robust nature of the technique despite the requirement to obtain first-order derivatives of real process steady state measurements with respect to controller set point values.