Structuring in liquid alkanes between solid surfaces : force measurements and mean-field theory

Measurements have been made of the solvation forces between mica surfaces in the even-numbered n-alkanes from hexane to hexadecane. In all cases the force law is qualitatively very similar, characterized by a decaying oscillatory function of distance, as occurs for simple isotropic liquids. The spacing between successive minima in the force does not increase with carbon number, and is comparable to the width of a linear alkane molecule rather than its length or any average diameter. This suggests that the alkanes have some tendency towards a parallel orientation near the mica surfaces. The measurements give no indication of any strong repulsive component expected from mean-field theories of higher alkanes or polymers. The results of one such theory are presented, and the reasons for its failure to match the experimental data are discussed.

Molecular alignment in nematic liquid crystals : a comparison between the results of experiments at high pressure and predictions based on mean field theories

The effects of high pressure on molecular arrangment in liquid crystals were observed by optical measurements on two nematogens. It was possible to deduce how volume varies as a factor of temperature and pressure and how nematic order parameter changes under the influence of high pressure.

Colloidal interaction between a rigid solid and a fluid drop

We present results of a theoretical study of the effect of surface deformation on a macroscopic system composed of a solid surface interacting with a fluid drop through electrostatic double-layer forces. The analysis involves numerically solving a Laplace equation suitably modified to describe the shape of a liquid drop subjected to a repulsive double-layer force. The latter is evaluated in nonlinear mean-field theory. Some analytical results are also given. The results indicate that although deformation need not be significant on the macroscopic scale, its effect on the interaction is significant and modifies the picture usually presented in DLVO theory. The decay length of the exponential repulsion deviates marginally from the Debye length, dependent on the interfacial tension of the drop. More significantly, at separations where the double-layer force becomes comparable to the internal pressure of the drop, the net force between the two bodies, the local radius of curvature of the drop, and the amount of deformation grow abruptly. The results of this work are relevant to emulsion stability, micelle, vesicle, and cell interactions, and recent experiments on bubble-particle interaction.

The determination of the local conditions for void initiation in front of a crack tip for materials with second-phase particles

A procedure is proposed to determine, for second-phase particles near a crack tip, the maximum particle stresses at the moment of void initiation by either particle fracture or particle/matrix interface separation. A digital image analysis system is applied to perform a quantitative analysis of corresponding fracture surface regions from stereo image pairs taken in the scanning electron microscope. The fracture surface analysis is used to measure, for individual particles, the crack tip opening displacement at the moment of void initiation and the particle location with respect to the crack tip. From these data, the stress tensor at the moment of void initiation is calculated from the Hutchinson–Rice–Rosengren (HRR) field theory. The corresponding average local stresses within the particle are evaluated by a non-linear Mori–Tanaka-type approach. These stresses are compared to estimates according to the models by Argon et al. [A.S. Argon, J. Im, R. Safoglu, Metall. Trans. 6 (1975) 825] and Beremin [F.M. Beremin, Metall. Trans. 12 (1981) 723]. The procedure is demonstrated on an Al6061–10% Al2O3 metal matrix composite.

Analytic prediction of structural stress-strain relations of microstructured metal

Nanostructured and ultra-fine grained metals have higher strength but extremely limited ductility compared to coarse grained metals. However, their ductility can be greatly improved by introducing a specific range of grain sizes in the microstructures. In the paper, multiscale unit cell approach (UCA) is developed and applied to predict the averaged stress-strain relations of the multiscale microstructure metals. The unit cell models are three-phase structured at different scale lengths of 100 nm, 1 μm and 10 μm with different volume fractions and periodic boundary conditions. The contributions of multi-scale microstructures to the macroscopic structural properties of metals are also studied using a analytic approach—two-step mean-field method (TSMF), where three microstructural parameters are introduced and thus mechanical properties such as strength and ductility are presented as a function of these parameters. For verification of these proposed numerical and theoretical algorithms, the structural properties of the pure nickel with three-grain microstructures are studied and the results from FEA and the proposed theory have good agreement.

The mediatization of the knowledge based economy : an Australian field based account

This paper presents an empirical account of mediatization from a Bourdieuian perspective, based on the development of a number of new concepts, such as cross-field effects and the rescaling of such effects as linked to processes of globalization. Built on an Australian empirical case relating to educational policy and the knowledge based economy, this paper argues that mediatization can be understood in relation to the cross-field effects of different fields of journalism on subsequent fields, which have their genesis in forms of practice that cross different social fields. Specifically, the case analysis details interactions between the field of print journalism and the field of policy over the course of an Australian science capability review, chaired by the then chief scientist, Dr Robin Batterham, which led to Australia adopting a national version of the knowledge economy. The empirical case also leads us to consider the impact of both global and national fields of journalism on fields of educational policy in relation to mediatization.

Sharpening the focus of force field analysis

The purpose is to explore the inherent complexity of Kurt Lewin's force field theory through applied analysis of organizational case examples and related methods. The methodology applies a range of tools from the consultancy research domain, including force field analysis of complex organizational scenarios, and applies bricolage and corroboration to emerging discoveries from semi-structured interviews, author experience, critical reflection and literature survey. Findings are that linear representation of internal and external forces in organizational applications of field theory does not fully explain the paradox of inverse vectors in the forces of change. The force field is not an impermeable thing; instead, it morphs. Examples of the inverse principle and its effects are detailed and extended in this analysis. The implications of the research are that force field analysis and related change processes promoted in organizational change literature run the risk of missing key complexities. The inclusion of the inverse principle can provide enhanced, holistic understanding of the prevailing forces for change. The augmentation of the early work of Kurt Lewin, and extension of previous analyses of his legacy in the Journal of Change Management and elsewhere, provide, in this article, change analysis insights that align well with current organizational environments.

A field model for repairing 3D shapes

This paper proposes a field model for repairing 3D shapes constructed from multi-view RGB data. Specifically, we represent a 3D shape in a Markov random field (MRF) in which the geometric information is encoded by random binary variables and the appearance information is retrieved from a set of RGB images captured at multiple viewpoints. The local priors in the MRF model capture the local structures of object shapes and are learnt from 3D shape templates using a convolutional deep belief network. Repairing a 3D shape is formulated as the maximum a posteriori (MAP) estimation in the corresponding MRF. Variational mean field approximation technique is adopted for the MAP estimation. The proposed method was evaluated on both artificial data and real data obtained from reconstruction of practical scenes. Experimental results have shown the robustness and efficiency of the proposed method in repairing noisy and incomplete 3D shapes.

Bringing Bourdieu to policy sociology : codification, misrecognition and exchange value in the UK context

The task of social scientists is to find ways of investigating and understanding the social, political and economic world, in order to offer insights into everyday and public life in the past, present and future. Bourdieu’s tool kit offers a particular way of theorizing the rules, narratives and self-held truths of social phenomena and of educational policy as a specific object of analysis. In this article I develop a series of propositions about the ways in which field theory might be applied to explain the abrupt public policy shift effected by the Thatcher government and the adjustments made to it by the Blair government. I suggest that a Bourdieuian approach shows policy working as a means of codification, as a doxa of misrecognition and as currency exchange within and across fields. I conclude with some thoughts about the difficulties of explicating interactions between fields.

Bourdieu and educational research: thinking tools, relational thinking, beyond epistemological innocence

The main aim of this chapter is to provide an introduction to the theoretical work of Pierre Bourdieu, and to outline different ways in which Bourdieu’s work is influential and has been engaged with in education research and to suggest implicitly the usefulness of this work for educational researchers. In order to do this, we draw on a range of Bourdieu’s own writing published singly or with colleagues, emphasising in particular his engagements with education. Part of our treatment also deals with his wider writing that has subsequently been influential for education researchers, and in particular Bourdieu’s anthropological writing and account of practice (Bourdieu 1977, 1990), his approach to social class and cultural issues, his account of the judgement of taste and distinctions (Bourdieu, 1984), and his later politically focused writing (Bourdieu, 1989/1996, 2003, 2004c, 2005a).

Mediatization and education: a sociological account

This chapter presents an account of the mediatization of education policy through a focus on the development and uptake of the knowledge economy discourse in national education policy and research settings. During the late 20th and early part of the 21st century, Australia, like other nation states around the globe, came to adopt the knowledge economy discourse as a kind of meta-policy that would help connect a variety of statistical indicators and provide direction for a number of policy areas, including education, science, and research funding. In Australia the adoption of a knowledge economy discourse was preceded by coverage from specialized sections of the quality print media, discussed broadly as a debate about the social contract that was afforded to fields charged with developing and producing national capacities for knowledge production. Such a debate mirrored similar claims by Michael Gibbons in the late 1990s, where he argued for a new social contract between science and society. Given the media coverage surrounding the uptake of the knowledge economy discourse and the promotion of the concept by the OECD, this chapter presents an account of the emergence of the knowledge economy discourse through a focus on the mediatization of the concept. The broad argument presented in this account is that what could be called “mediatization effects”, related to the promotion and adoption of policy concepts, are variable, and reach the broader public in inconsistent, time-bound, and sporadic patterns. In order to understand mediatization effects in respect of policy, the paper draws on a broad Bourdieuian informed conceptual framework to understand different kinds of fields, their logics of practice, and importantly here, cross-field effects. Specifically, the focus is on those cross-field effects related to the impact of practices within both national and global fields of journalism on national and global fields of education policy. While the case is an Australian one, the account explores general and more broadly applicable ways to understand links between the globalization and the mediatization of policy.

Contribution of twinning to low strain deformation in a Mg alloy

Deformation twinning plays an important role in the yielding of extruded magnesium alloys, especially when loaded in compression along the extrusion axis. The magnitude of this contribution is not accurately known. The present study employs electron backscatter diffraction to reveal the influence of grain orientation on twin-volume fraction for alloy AZ31 tested in compression to strains between 0.008 and 0.015. For these strains, it is seen that approximately 45 pct of the deformation can be attributed to "tensile" twinning. The variation of twin-volume fraction over different orientation classes correlates closely with the maximum Schmid factors for both tensile twinning and basal slip. These effects are readily explained quantitatively using a mean field crystal plasticity model without recourse to stochastic effects. Encouraged by this, we introduce an analytical approximation based on the uniformity of (axial) work. © 2013 The Minerals, Metals & Materials Society and ASM International.

Aiding journalism: Australian journalism educators and their work in post conflict states

 Dr Wake presents a comprehensive thesis of Australian journalism education and training in the context of foreign aid and policy, particularly as applied in the Solomon Islands. Although it is essentially about journalism, the thesis also adds to the field of development studies. Dr Wake has used Bourdieu’s field theory to underpin her critical analysis.