Showing papers by "City University London published in 1977"
TL;DR: Investigators studying the applicability of “Lotka's law” to the humanities and to map librarianship may have misinterpreted Lotka's Law and concluded erroneously that the law applies to these fields.
Abstract: In 1926, Alfred Lotka examined the frequency distribution of scientific productivity of chemists and physicists. After analyzing the number of publications of chemists listed in Chemical Abstracts 1907–1916 and the contributions of physicists listed in Auerbach's Geschi-chtstafeln der Physik, he observed that the number of persons making n contributions is about 1/n2 of those making one and the proportion of all contributors that make a single contribution is about 60%. Recently, investigators studying the applicability of “Lotka's law” to the humanities and to map librarianship may have misinterpreted Lotka's law and have concluded erroneously that the law applies to these fields. Corrected calculations indicate that Lotka's law does not apply.
200 citations
TL;DR: In this article, a series of M(I) and M(III) polypyridyl complexes have been prepared by controlled potential electrolysis; these include a number of 3+ and 1+ oxidation state complexes of nickel which have not previously been isolated.
49 citations
TL;DR: This article explored the extent and accuracy of the subject's knowledge of his previous recall performance as a function of response mode and response-produced feedback and found that impaired feedback led to poorer knowledge of previous recall in each response mode.
49 citations
TL;DR: In this article, a single side branch Helmholtz resonator has been tested in a circular duct in which both sound and an air flow could be passed in the same direction, and the transfer function across the resonator was determined by using two microphones and a cross-correlation analysis technique in which the broad band sound input was cross correlated with each microphone signal in turn.
32 citations
23 citations
TL;DR: The results indicate that, in patients with compensated cirrhosis, the efficiency of the liver in extracting unconjugated bilirubin from plasma against a concentration gradient is impaired, even though the liver's capacity to conjugate bilirUBin may be normal.
Abstract: 1. The kinetics of unconjugated [ 14 C]-bilirubin metabolism have been investigated and analysed in terms of a three-pool model in a group of seven normal subjects and in a group of eight cirrhotic patients who had appreciable impairment of liver cell function. 2. In the patients with cirrhosis, the plasma unconjugated bilirubin was either normal or only slightly increased but the metabolism of unconjugated bilirubin was deranged. 3. The mean volume of distribution, the mean 4 h retention, and the mean mass of the rapidly mixing pool were all significantly greater than in the normal subjects. In contrast, mean fractional clearance rate and mean estimated erythrocyte life-span were significantly less than in the normal subjects. 4. The mean fractional transfer rates and fluxes from pool 1 (rapidly mixing pool—‘plasma’) to pool 3 (‘extravascular’) and vice versa were significantly greater than the corresponding values in the normal subjects. 5. The results indicate that, in patients with compensated cirrhosis, the efficiency of the liver in extracting unconjugated bilirubin from plasma against a concentration gradient is impaired, even though the liver9s capacity to conjugate bilirubin may be normal. As a consequence of the increased volume of distribution, the absolute hepatic clearance of unconjugated bilirubin is relatively well maintained.
12 citations
30 Jun 1977
TL;DR: In this paper, it was shown that if the speed of the inner cylinder is increasing slowly then the growth rate for an axisymmetric disturbance is reduced considerably compared with that calculated by using a steady base flow.
Abstract: We have applied the W.K.B. type of approximation to the stability of flow between concentric cylinders when the speed of rotation is varying slowly. For the case of a fixed outer cylinder we have shown that if the speed of the inner cylinder is increasing slowly then the growth rate for an axisymmetric disturbance is reduced considerably compared with that calculated by using a steady base flow. This leads to an increase of the Taylor number at which growth would first occur of the order of 20 % in cases where the theory seems applicable. We have also obtained results for a small sinusoidal modulation of low frequency to the inner cylinder velocity. These confirm Hall’s (1975) results of slight destabilization, almost independent of the frequency.
12 citations
TL;DR: In the U.K., following the publication of the Radcliffe Report, it was widely believed that monetary policy was impotent because any attempt to make use of monetary policy would be fully offset by perfect money substitutes which were not controlled by the monetary authorities as discussed by the authors.
10 citations
TL;DR: Analysis of passive mechanisms are adequate for the human kidney but may be inadequate for other mammalian species, according to a comprehensive mathematical model of the renal medulla presented and validated.
9 citations
TL;DR: Small but significant changes in accommodation were found with ephedrine and reversed by thymoxamine, suggesting that they were mediated through alpha-adrenoceptor activity.
Abstract: In a study in 12 healthy volunteers, local instillation of thymoxamine eye-drops (0.2%) completely reversed the mydriasis produced by ephedrine (5%) but not that produced by ephedrine (5%) together with tropicamide (0.5%). Small but significant changes in accommodation were found with ephedrine and reversed by thymoxamine, suggesting that they were mediated through alpha-adrenoceptor activity. The thymoxamine eyedrops were well tolerated.
9 citations
TL;DR: In this paper, it was shown that, under conditions where heat transfer in the reacting gases takes place solely by conduction, temperature limits for ignition are in excellent agreement with predictions according to the conductive theory of thermal ignition.
Abstract: Measurements of temperature changes in decane-air mixtures near the critical boundary for spontaneous ignition indicate that, under conditions where heat transfer in the reacting gases takes place solely by conduction, temperature limits for ignition are in excellent agreement with predictions according to the conductive theory of thermal ignition. It is shown, however, that, by use of a derived relation between the dimensionless rate of heat release and the Rayleigh number, thermal ignition theory can be extended to the prediction of temperature limits under conditions where considerable convective heat transfer also takes place. Furthermore, the overall activation energy of the initial reactions involved in the oxidation of other alkanes has been shown to be a useful parameter for the prediction of the corresponding spontaneous ignition temperature limits.
TL;DR: In this paper, a hypodermic battery method was developed for generating relatively large droplet suspensions, consisting of reasonably uniformly sized droplets, in sufficiently high concentrations for flame propagation.
01 Jun 1977
TL;DR: In this paper, entry-length heat transfer to upward laminar flow with combined convection in a vertical tube is taken as typical, and a comparison is made between measured values and, first, a full numerical solution for constant thermophysical properties (viscosity and thermal diffusivity), secondly, the same solution but allowing for their individual and combined variation with temperature and, thirdly, a solution which assumes a series of truncated versions of the fully developed temperature distribution to establish corresponding velocity profiles, allowing for temperature-dependent properties.
Abstract: Numerical techniques for the calculation of velocity and temperature distributions in heated ducts have proved accurate but expensive in computer time and capacity. It is worth investigating to what extent simplification is possible without loss of accuracy. Entry-length heat transfer to upward laminar flow with combined convection in a vertical tube is taken as typical. Comparison is made between measured values and, first, a full numerical solution for constant thermophysical properties (viscosity and thermal diffusivity), secondly, the same solution but allowing for their individual and combined variation with temperature and, thirdly, a solution which assumes a series of truncated versions of the fully developed temperature distribution to establish corresponding velocity profiles, allowing for temperature-dependent properties.
TL;DR: The Skraup synthesis with m -ethylaniline has been shown to give a mixture of 7-ethylquinoline (75%) and 5-methyl-and 5-ethyl-quinoline derivatives.
TL;DR: The general problems of validating control system models in physiology result from inadequate structural knowledge and inadequate initial estimates of system parameters, and two approaches to their solution are described.
TL;DR: In this article, preliminary attempts to develop inexpensive, protective conducting coatings on mild steel for use as insoluble anodes are described from the consideration that a mixture of acid resistant semiconducting oxide and glass might form a satisfactory coating when heated on a steel substrate, Sb-SnO2 and Ti-Fe2O3 were selected as conducting oxide materials for evaluation.
Abstract: Preliminary attempts to develop inexpensive, protective conducting coatings on mild steel for use as insoluble anodes are described From the consideration that a mixture of acid resistant semiconducting oxide and glass might form a satisfactory coating when heated on a steel substrate, Sb-SnO2 and Ti-Fe2O3 were selected as conducting oxide materials for evaluation With 3–30 wt% glass added to the oxides, Sb-SnO2 was found to be unsuitable as pellets of the glass-oxide mixture did not densify on heating up to 1400° C 3% Ti-Fe2O3 plus 20% glass pellets fired at 1250° C showed low resistivity and porosity An oxide-glass mixture of this composition fired on a mild steel substrate at 1250° C gave a coating with a porosity of ∼ 05%, on which chlorine could be evolved in HCl solution The Ti-Fe2O3 oxides were very acid resistant under conditions of chlorine evolution A reduction in the porosity of the coating, or the use of an acid resistant metal substrate, would be required to make the oxide-glass coating a practicable proposition
01 Feb 1977
TL;DR: In this article, the authors describe the properties of homocysteic acid (DLH), C4H9NO5S (C4H 9NO 5S), and DLH-DLH.
Abstract: dl-Homocysteic acid (DLH), C4H9NO5S. Melting point 274–276 °C. Space group and cell dimensions:F2dd;as = 6.06(3),b = 20.19(7),c = 23.25(5) A,Z = 16,Dx = 1.709 g cm−3,Dc = 1.711 g cm−3.
TL;DR: A cybernetic model for the study of blood glucose dynamics is presented, making use of known enzymological data, that permits study of the metabolic and endocrine processes involved in the system's response.
01 Dec 1977
TL;DR: The origins and growth of the use of CCTV at Worcester Polytechnic Institute are described in this paper, together with the present range of activities and the special facilities created to allow easy preparation of this material, either as a straightforward lecture or in a classroom situation with feedback, are dealt with.
Abstract: The origins and growth of the use of CCTV at Worcester Polytechnic Institute are described, together with the present range of activities. VCR material forms an important component in many courses: the special facilities created to allow easy preparation of this material, either as a straightforward lecture or in a classroom situation with feedback, are dealt with
TL;DR: In this paper, the results obtained from the continuous operation of a two inch-diameter column crystallizer and scale-up considerations involved in the design of a four inch column are presented.
TL;DR: A comprehensive mathematical model of the human respiratory system is presented that is capable of reproducing events occurring within the respiratory cycle and can be used as a test-bed for examining alternative hypotheses regarding the nature of the chemical control of breathing.
TL;DR: In this paper, the authors describe a successful attempt to control a simple laboratory-scale plant using a multivariable algorithm designed using the Inverse Nyquist Array technique, which reduced the interactions to a negligible level and gave good control under a variety of conditions.
TL;DR: The model provides a test-bed with which to explain and predict the effects of drug injections on the human cardiovascular system and is suitable for the study of short-term blood dynamics.
01 Jan 1977
TL;DR: In this article, the application of plasticity theory to the quasi-static, plane strain deformation of essentially an isotropic, rigid material was considered, and the differential equations for force equilibrium and for strain-rate were hyperbolic.
Abstract: The preceding chapter considered the application of plasticity theory to the quasi-static, plane strain deformation of essentially an isotropic, rigid—perfectly plastic material. For some applications, allowance was made for the strain-hardening of engineering metals by means of a technological approach. The differential equations for force equilibrium and for strain-rate are hyperbolic. This enables the method of the slip line field technique to be used for the solution of a number of problems and the knowledge required to solve these problems is now well developed.
01 Jan 1977
TL;DR: In the theory of plasticity, a number of general theorems have an important role and the most important of these are the theorem on the extremum properties of a solution or extremum principles.
Abstract: In the theory of plasticity a number of general theorems have an important role and the most important of these are the theorems on the extremum properties of a solution or extremum principles and the so-called uniqueness theorems. These theorems permit the possibility of the direct construction of solutions which do not demand the integration of the differential equations of equilibrium. This possibility is very important because in plasticity the problems are usually nonlinear.
01 Jan 1977
TL;DR: In this paper, the authors derived first approximations to the force, energy and power required to perform a metal forming operation and also provided useful information about the manner in which the workpiece material deforms.
Abstract: In previous chapters, plastic deformation of an element of material on a microscopic scale was considered as though the element were independent of the body of material. For many metal forming processes such as forging, drawing and rolling the geometrical configuration of the tooling, frictional conditions at the workpiece—tooling interfaces and the constraint of neighbouring material will result in the plastically deforming region being subjected to a field of stress and strain which may differ from point to point. This field of stress—strain states makes it extremely difficult to obtain a solution to a problem. Only by making certain assumptions is it possible to derive good first approximations to the force, energy and power required to perform a metal forming operation and also provide useful information about the manner in which the workpiece material deforms.
TL;DR: In this paper, the generalized Landau equation is linearized and then solved within CPA for PdFe, PdNi, and PtNi alloys at finite temperatures.
Abstract: The Landau model [1] is applied to PdFe, PdNi, and PtNi alloys at finite temperatures. The generalized Landau equation is linearized and then solved within CPA. The temperature dependence is incorporated via the Landau parameter A ( T ). The model explains well the temperature dependence of the susceptibility and the concentration dependences of the magnetization and T c .