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Showing papers by "University of Bath published in 1981"


Journal ArticleDOI
Adrian Bowyer1

1,105 citations



Book ChapterDOI
TL;DR: In this paper, the authors focus on variational and related methods for the overall properties of composites, such as fiber-reinforced composites or polycrystals, whose properties vary in a complicated fashion from point to point over a small, microscopic length scale, while they appear on average to be uniform.
Abstract: Publisher Summary This chapter focuses on variational and related methods for the overall properties of composites. A wide range of phenomena that are observable macroscopically are governed by partial differential equations that are linear and self-adjoint. This chapter is concerned with such phenomena for materials, such as fiber-reinforced composites or polycrystals, whose properties vary in a complicated fashion from point to point over a small, “microscopic” length scale, while they appear “on average” (that is, relative to the larger, macroscopic scale) to be uniform. This chapter treats the elastic behavior of composites, and emphasizes that a number of other properties (conductivity, viscosity of a suspension, etc.) are described by the same equations. Extensions to viscoelastic and thermoelastic behavior are presented, for both of which the variational characterization given is believed to be new. Problems, such as the resistance to flow of viscous fluid through a fixed bed of particles are mentioned, and a model problem that involves diffusion is presented in some detail. This displays the same difficulty in relation to divergence of an integral and is one problem of this type that has so far been approached variationally. Methods related to the Hashin–Shtrikman variational principle are also described in the chapter.

832 citations


Journal ArticleDOI
TL;DR: In this paper, the Hashin-Shtrikman principle in the static limit is used to derive variational principles for elastodynamic problems, which reduce to the hashin-shtein principle.

221 citations


Journal ArticleDOI
TL;DR: In this article, the authors describe research concerned with assisting groups in organizations handle their complex, ill-structured policy issues in ways which are significantly different from many typical policy analysis projects.
Abstract: This paper describes research concerned with assisting groups in organizations handle their complex, ill-structured policy issues in ways which we believe are significantly different from many typical policy analysis projects. It is our belief that many systems research, operational research and management science projects have concentrated on ‘objective’, usually quantitative data at the expense of losing their clients' interest and commitment. Our work is concerned with taking account of intersubjectivity in policy analysis and evaluation. It is orientated to the construction of models that will be owned by our clients because they recognize as legitimate, and explicitly take account of, the subjective and particular knowledge of individuals within organizations. They also explicitly take account of the interaction of shared and individual knowledge as a group comes to define an intersubjective group issue.

103 citations



Book ChapterDOI
TL;DR: This chapter explores that the citric acid cycle was accepted as the terminal pathway for the oxidation of foodstuffs in all respiring animal tissues and concentrates heavily on aspects of citrate synthase and succinate thiokinase.
Abstract: Publisher Summary This chapter explores that the citric acid cycle was accepted as the terminal pathway for the oxidation of foodstuffs in all respiring animal tissues. The scheme of the cycle originally proposed still holds good, though it required the discovery of coenzyme A and the elucidation of the roles of acetyl-CoA and succinyl-CoA as intermediates for the cycle to be elaborated to the expanded form in which now it is known. The application of procedures successfully adopted with animal tissues to demonstrate the occurrence of the citric acid cycle in microorganisms were initially unsuccessful and were hampered by the permeability barriers toward metabolites and inhibitors, which microorganisms possess to a more marked extent than animal tissues. The problems encountered and the ways in which the cycle was finally established as the major pathway of terminal respiration in microorganisms have been reviewed. It concentrates heavily on aspects of citrate synthase and succinate thiokinase. The emphasis is on the variations displayed by the enzymes from different organisms around a common catalytic theme.

96 citations


Journal ArticleDOI
TL;DR: The authors presented an analysis of the distributive impact of government expenditures in the United States using a household-level microdata file drawn from the 1970 U.S. Census of Population.
Abstract: This paper presents an analysis of the distributive impact of government expenditures in the United States. The analysis uses a household-level microdata file drawn from the 1970 U.S. Census of Population, with additional income and tax variables drawn from the Internal Revenue Service 1969—70 Tax File. The results are presented at both federal and local levels and include analyses of the distribution of individual benefits, as well as of overall taxes and net benefits. Since a microdata file was used, distributional effects are examined with respect not only to the “traditional” variables of income class and household size, but also with regard to the number of earners in the household and the sex and race of the household head. In a further paper in a subsequent issue of this review we will present the results of a similar analysis for the United Kingdom, and compare the results for the two countries.

96 citations


Journal ArticleDOI
TL;DR: In this article, the impact force on a sphere striking a horizontal liquid surface vertically at speeds in the range 1-3 m s−1 was investigated. And the impact drag coefficient was also studied through the transition from inertia to viscosity-dominated conditions.
Abstract: Detailed experimental results are presented for the initial impact force on a sphere striking a horizontal liquid surface vertically at speeds in the range 1-3 m s−1. Results are discussed in terms of an impact drag coefficient. Liquids having viscosities in the range 10−3−102 Pa s have been studied. For low viscosities the results have been compared with the theoretical calculations of Shiffman & Spencer. Good agreement has been found in most respects; in particular the impact force varies as the square root of the depth for depths less than a tenth of the radius. The impact drag coefficient has also been studied through the transition from inertia to viscosity-dominated conditions. The variation of the impact drag coefficient is presented as a function of Reynolds number, and its variation in the range 5 × 10−2 < Re < 5 × 103 is shown to resemble that of a fully immersed sphere moving steadily in a homogeneous fluid.

92 citations


Journal ArticleDOI
TL;DR: In this paper, the authors define the Normal Programme as all explanations of scientific knowledge which do not obey the methodological prescriptions of the Radical Programme and analyze the normal programme explanations into two basic sorts of explanations, rational-actor and hidden-hand explanations.
Abstract: In the introduction to the paper I describe the ‘Radical Programme’ in the sociology of scientific knowledge. This is part of Bloor’s ‘Strong Programme’. I suggest that certain tenets of the Strong Programme are unnecessary. In the second part of the paper I draw out the methodological implications of the Radical Programme. In the third part, I define the ‘Normal Programme’ as all explanations of scientific knowledge which do not obey the methodological prescriptions of the Radical Programme. The Normal Programme is then analyzed into two basic sorts of explanation, ‘rational-actor’ explanations and ‘hidden-hand’ explanations. I then examine sources of data on truth, rationality, success and progressiveness of facts, theories and acts since, such data are needed in Normal Programme explanations. I conclude that such data are empty or unreliable when used in rational-actor explanations and that such explanations should be avoided. Thus, irrespective of epistemological preference the only alternative to Radical Programme explanations are hidden-hand explanations.

91 citations


Journal ArticleDOI
TL;DR: The results show that the adipocyte sugar transport system handles 3-O-methyl-D-glucose symmetrically, and that insulin does not change either the internal or the external affinity constants for this glucose analogue.

Journal ArticleDOI
Ian Colville1
TL;DR: In this paper, it is argued that most accountants have based their behavioural research on the natural scientific approach, a paradigm whose relevance and suitability for conducting social research has been increasingly questioned in recent years.
Abstract: This paper adopts a critical stance towards behavioural accounting research methodology. It is argued that most accountants have based their behavioural research on the natural scientific approach, a paradigm whose relevance and suitability for conducting social research has been increasingly questioned in recent years. The author discusses some alternatives to the positivistic research methodology of the natural sciences as a way of developing social science and the implications these have for providing a coherent theoretical and methodological perspective for future “behavioural accounting” research. It is the contention of this paper that the study of the behavioural aspects of accounting has largely failed to develop into a coherent theoretical or practical body of knowledge. In an attempt to overcome this state of affairs, there is an increasing trend to employ organizational and sociological theory as a basis for research, as opposed to psychology and social psychology which informed earlier conceptual thinking and research. While accountants may see this conceptual development as an advancement in that it locates accounting processes in their organizational and social contexts, the way in which it is being conducted is criticized in this paper because, like psychology, it is characterized by an essentially positivistic methodology. This article will first provide a broad overview of the relationship between accounting research and the behavioural sciences. From that overview it will be argued that accounting researchers are unlikely to make much progress by borrowing behavioural scientific concepts unless they develop a deeper understanding of the philosophical underpinnings of these concepts and the competing schools of methodological thought which exist within the behavioural sciences. In an attempt to fill this apparent gap in understanding, the paper will discuss the scientific approach of the natural sciences, why it is felt to be inappropriate for the behavioural sciences and what alternatives exist.

Journal ArticleDOI
TL;DR: In this article, a modified Born stability criterion that 1 2 (C 11 − C 12 ) B equals about 0.2 is reached at the phase transition pressure P t, and the ratio β t α t of the second-order bond-bending β t to bond-stretching α t, force constants is about 1.1.

Journal ArticleDOI
TL;DR: Evidence is provided for the involvement of at least two different forms of cytochrome P-450 in antipyrine metabolism in man and clearance to norphenazone was increased to a much greater extent than to either of the other two metabolites.
Abstract: Antipyrine is oxidised to three main metabolites in man. There is evidence that the different metabolites are products of different forms of cytochrome P-450. The effect of rifampicin administration for two weeks on the rates of formation of these metabolites was investigated in healthy volunteers. Rifampicin increased antipyrine clearance and shortened its half-life. Two weeks after stopping rifampicin the induction had largely been reversed. Clearance to all three metabolites was increased by rifampicin. Clearance to 3-hydroxymethylantipyrine was increased from 7.8±0.9 ml/min to 13.3±1.3 ml/min, to norphenazone from 5.8±0.6 ml/min to 19.3±2.1 ml/min and to 4-hydroxyantipyrine from 14.3±2.2 ml/min to 21.9±3.9 ml/min. Thus clearance to norphenazone was increased to a much greater extent than to either of the other two metabolites. It is concluded that this provides evidence for the involvement of at least two different forms of cytochrome P-450 in antipyrine metabolism in man.

Journal ArticleDOI
TL;DR: This paper presented an analysis of the distributive impact of public expenditures and taxes in the United Kingdom using household level microdata from the 1971 Family Expenditure Survey, with tax and expenditure aggregates drawn from the national accounts.
Abstract: This paper presents an analysis of the distributive impact of public expenditures and taxes in the United Kingdom. The analysis uses household level microdata from the 1971 Family Expenditure Survey, with tax and expenditure aggregates drawn from the national accounts. The analysis is the first to allocate all taxes and public expenditures for the United Kingdom, and the results are compared to those from the more restricted analyses carried out by the U.K. Central Statistical Office. Results are presented for individual taxes and benefits as well as for overall net benefits and they describe distributional effects with respect to income class, household size, number of earners and housing tenure. A final section of the paper compares the results to those from a similar analysis for the United States which were reported in the previous issue of this review.

Journal ArticleDOI
TL;DR: In this article, the compressive strength of aligned fiber composites depends linearly on the volume fraction of the fiber and the average angle of misalignment of the fibres.
Abstract: Experiments carried out on pultruded fibre reinforced polyester resins show that, at moderate fibre volume fractions, the compressive strength of aligned fibre composites depends linearly on the volume fraction. The strength falls off when the fibre volume fraction,V f=0.4 with Kevlar and high strength carbon fibres. The effective fibre strength atV f<0.4 is much less than the tensile strength but it is close to the tensile strength with E-glass fibres and high modulus carbon fibres. Poor adhesion between fibres and matrix reduces the compressive strength, as does kinking the fibres when the fibre radius of curvature is reduced to below 5 mm. Misalignment of the fibres reduces the compressive strength when the average angle of misalignment exceeds about 10° for glass and carbon fibres. However, with Kevlar no such reduction is observed because the compression strength of Kevlar reinforced resin is only a very little better than that of the unreinforced resin.

Journal ArticleDOI
TL;DR: A simple procedure for detecting interfertility between Stereum isolates is described, which may facilitate an experimental taxonomic approach hitherto thought impossible for StereUM due to the widely held belief that members of the genus are homothallic.
Abstract: Single basidiospore isolates from different fruit bodies of Stereum hirsutum always produced a morphologically distinct secondary mycelium when paired in culture. This type of mycelium was only formed in certain crosses between sibs, and the strains belonged to two incompatibility groups, indicating that the species is heterothallic. Secondary mycelia obtained from various compatible combinations of non-sibs were always strongly antagonistic when paired. Field isolates from fruit body tissue or wood were similarly antagonistic if obtained from different columns of decay in the same log or from separate localities, indicating that they represented separate heterokaryotic individuals. An unusual reaction occurred in about one-third of the incompatible pairings between sibling monospore mycelia. This took the form of a band of appressed, sparse mycelium, widest at the ends, and bounded by narrow regions of exuded droplets. These bands usually expanded unilaterally, with one of the isolates partially or totally replacing the other. In some cases this expansion stopped along a line where typical antagonism later developed. On the basis of these reactions, a simple procedure for detecting interfertility between Stereum isolates is described. This may facilitate an experimental taxonomic approach hitherto thought impossible for Stereum due to the widely held belief that members of the genus are homothallic.

Journal ArticleDOI
TL;DR: The results indicate that the important hydrogen bonding positions involved in sugar interaction with the insulin-stimulated adipocytes transporter are the ring oxygen, C-1 and C-3.

Journal ArticleDOI
TL;DR: Bacteria in the anterior regions of the Gut of Schistocerca gregaria were restricted to the lumen and inside of the peritrophic membrane, however, in the hindgut, bacteria were also associated with the cuticular lining.

Journal ArticleDOI
TL;DR: This paper found that women who believed themselves to be in personal control of their lives experienced shorter labours with more intense pain per hour than those who believed in the uncontrollability of events.

Journal ArticleDOI
01 Jan 1981-Scanning
TL;DR: In this paper, a review of sources of contamination and methods of minimising the problem is presented, where the authors discuss methods of minimizing the problem of carbonaceous deposit on the specimen undergoing analysis or condensation and polymerization of extraneous matter upon other components of the instrument.
Abstract: Contamination in electron optical equipment may occur in the form of carbonaceous deposit on the specimen undergoing analysis or condensation and/or polymerisation of extraneous matter upon other components of the instrument. Almost without exception these effects are undesirable and in this paper we review sources of contamination and discuss methods of minimising the problem.

Journal ArticleDOI
TL;DR: In this paper, Pultruded fiber composite rods have been made from polyester resin and mixtures of carbon, Kevlar and glass fibres, and the strengths and elastic moduli of the hybrids were not always as predicted by the mixtures rule, moduli in particular often being lower than expected.
Abstract: Pultruded fibre composite rods have been made from polyester resin and mixtures of carbon, Kevlar and glass fibres. The strengths and elastic moduli of the hybrids were not always as predicted by the mixtures rule, moduli in particular often being lower than expected. The addition of relatively little carbon fibre to a Kevlar composite drastically reduces its ductility. Glass has a less significant effect, and some glass-Kevlar composites show a secondary elastic modulus.

Journal ArticleDOI
TL;DR: In this article, the authors explored the notion that many existing studies which show moderate relationships between role variables and stress symptoms are doing so because of the operational similarity of independent and dependent variables, and predicted that the removal of such an artefact by clearly separating the two sets of variables would result in a nil relationship.
Abstract: SUMMARY This study explores the notion that many existing studies which show moderate relationships between role variables and stress symptoms are doing so because of the operational similarity of independent and dependent variables. It was predicted that the removal of such an artefact by clearly separating the two sets of variables would result in a nil relationship. Matched 'cases' and 'controls' were compared in two different organizations. The independent judgments of occupational health specialists were used to measure stress on a number of agreed dimensions, and role measurements were taken by the researchers in three different ways. On all comparisons made there was a strong trend suggesting no role/stress associations. The implications of the results for role stress studies are discussed.

Journal ArticleDOI
TL;DR: Di-μ-chlorobis (N,N-dimethyl-3,4-dimethoxybenzylamine-6-C,N) reacts readily with a variety of styrenes to give good yields of the corresponding o-aminomethylstilbene derivatives as mentioned in this paper.

Journal ArticleDOI
TL;DR: Walls from various species had a differential effect on the rate and extent of synthesis of some enzymes over 15 days, but this showed no consistent relationship with compatibility or incompatibility of the host-parasite interaction, and binding or inactivation of PG and PL by cell walls was investigated.
Abstract: The role of plant cell walls in non-host resistance was examined by determining their influence on production and activity of polygalacturonases (PG) and pectin lyases (PL) from 6 fungal pathogens able to cause significant wall degradation in vivo. Botrytis fabae, B. cinerea, Sclerotinia fructigena, S. trifoliorum, Fusarium oxysporum f.sp. lycopersici and F. oxysporum f.sp. pisi were grown in shake cultures containing as sole carbon source cell walls extracted from host and non-host plants (broad bean, tomato, apple, clover, pea and dwarf bean). Walls from various species had a differential effect on the rate and extent of synthesis of some enzymes over 15 days, but this showed no consistent relationship with compatibility or incompatibility of the host-parasite interaction. Thus greatest PG production by B. fabae, B. cinerea and F. oxysporum f.sp. lycopersici was on host cell walls, whereas walls from host plants supported the lowest accumulation of PL by F. oxysporum f.sp. lycopersici, PL by F. oxysporum f.sp. pisi and PG by S. fructigena. Occasionally enzyme levels were especially low during growth on non-host walls, e.g. B. fabae PG with apple and F. oxysporum f.sp. pisi PG on clover. Growth of F. oxysporum ff.sp. varied on cell walls from different species but was not related to enzyme production or host-parasite compatibility. Binding or inactivation of PG and PL by cell walls was investigated with 3 wall preparations extracted to contain: inactivated wall proteins; covalently-linked but not ionically-bound proteins; total wall proteins. Incubation with cell walls usually reduced soluble enzyme activity, e.g. ≤30% for PG of A. niger, Botrytis spp. and S. fructigena, ≤60% for F. oxysporum ff.sp. PG, ≤86% for PL of F. oxysporum ff.sp., ≤93% for PG from S. trifoliorum. Often much of the lost activity could be recovered by desorptiou with 0·2 M NaCl; however, complete activity was not always regained which could suggest inactivation or firmer binding. Cell walls containing ionically-bound proteins were not consistently more inhibitory than other wall preparations, except against PG from F. oxysporum ff.sp. Walls without active proteins were often equally effective in reducing activity. Effects of walls from host and non-host plants were essentially similar. These findings are discussed in relation to non-host resistance, PG inhibitors in cell wa ll and the restriction of wall-degrading enzymes during pathogenesis.

Journal ArticleDOI
TL;DR: The phonetic realizations of ain't in Reading English do not accord with traditional etymologies, depending more on the syntactic environment in which ain't occurs than on the standard English forms from which they are usually assumed to derive as mentioned in this paper.
Abstract: Ain't occurs as a sociolinguistic variable in working class speech in the town of Reading, England. The phonetic realizations of ain't in Reading English do not accord with traditional etymologies, depending more on the syntactic environment in which ain't occurs than on the standard English forms from which they are usually assumed to derive. The phonetic variants are also marked for semantic function in tag questions. Variation in the use of ain't can be explained as reflecting an ongoing linguistic change (sociolinguistics, dialectology, language change, theoretical linguistics).

Journal ArticleDOI
TL;DR: In this article, measurements have been made of the pressure and temperature dependences of the velocities of longitudinal and transverse ultrasonic waves in a glass having the composition 0.58ZrF 4 : 0.08ThF 4.

Journal ArticleDOI
TL;DR: Some of the key differences and similarities they found between this work in the community and more traditional organizations, particularly in terms of client-consultant expectations and their "organizational" context are discussed.
Abstract: For the past eighteen months the authors have been involved in work with a community group attempting to help the unemployed youth of their small city. This paper discusses some of the key differences and similarities they found between this work in the community and more traditional organizations, particularly in terms of client-consultant expectations and their "organizational" context. The authors were made aware of the inadequacy of traditional O.R. techniques for helping their clients and the paper also describes some of the unconventional methods they were forced to turn to in order to offer realistic and relevant help with this complex "mess" of multiple problems, nested feedback loops and subjective, political beliefs not amenable to quantification.

Journal ArticleDOI
TL;DR: Simultaneous and sequential inoculation of sexually compatible monokaryons on to agar demonstrated that growth rate of the monokARYons and patterns of dikaryotization and nucleus migration between them are likely to be crucial determinants of the spatial distribution of dkaryons in a population.
Abstract: were similar to those found in natural populations of the fungus, with individual dikaryons present in discrete regions delimited by zones of mutual antagonism. Different dikaryons had similar growth rates and occupied approximately equal areas or volumes when inoculated simultaneously on to agar or into wood respectively. Simultaneous and sequential inoculation of sexually compatible monokaryons on to agar demonstrated that growth rate of the monokaryons and patterns of dikaryotization and nucleus migration between them are likely to be crucial determinants of the spatial distribution of dikaryons in a population. Monokaryons inoculated into logs in the field quickly became dikaryotized, and the resulting dikaryons contained diverse mating-type factors indicating the presence of a heterogeneous spore rain.

Journal ArticleDOI
Ravi Prakash1
TL;DR: In this article, a number of CFRP specimens having different ultrasonic attenuation values were tested in fatigue, and fracture surfaces were studied using a scanning electron microscope (SEM).